diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..08c11d6
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,9 @@
+module github.com/gopherdojo/dojo6
+
+go 1.12
+
+require (
+	github.com/google/go-cmp v0.3.1
+	github.com/pkg/errors v0.8.1
+	golang.org/x/sync v0.0.0-20190423024810-112230192c58
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..968da45
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,6 @@
+github.com/google/go-cmp v0.3.1 h1:Xye71clBPdm5HgqGwUkwhbynsUJZhDbS20FvLhQ2izg=
+github.com/google/go-cmp v0.3.1/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58 h1:8gQV6CLnAEikrhgkHFbMAEhagSSnXWGV915qUMm9mrU=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
diff --git a/kadai3-2/en-ken/Readme.md b/kadai3-2/en-ken/Readme.md
new file mode 100644
index 0000000..08eaa2c
--- /dev/null
+++ b/kadai3-2/en-ken/Readme.md
@@ -0,0 +1,39 @@
+# 課題3-2
+
+## 分割ダウンローダを作ろう
+
+- Rangeアクセスを用いる
+- いくつかのゴルーチンでダウンロードしてマージする
+- エラー処理を工夫する
+  - golang.org/x/sync/errgroupパッケージなどを使ってみる
+- キャンセルが発生した場合の実装を行う
+
+## 使い方
+
+```
+go get github.com/gopherdojo/dojo6/kadai3-2/en-ken/dl-mgr
+div -n [goroutineの並列数(デフォルト:5)] -o [保存ファイル名(デフォルト:リモート名)] URL
+```
+
+## やったこと
+
+1. HEADリクエストしてAccept-Rangesヘッダの有無確認
+1. Accept-Rangesがあった場合、
+    1. 任意の分割数に応じて、goroutineごとの割当範囲を決めて、各goroutineでRange GET
+    1. 部分ファイルに出力
+1. 全部ダウンロードできたら、ファイルをマージして部分ファイル削除
+
+## 工夫した点
+
+- 1つのgoroutineがダウンロードするデータが1MBを超えた場合、1MBごとにファイル出力する。
+- Rangeアクセスに対応していなかったら普通にダウンロードする。
+- すでにダウンロード済のデータがあった場合(そのパートのファイルがあった場合)、それを再利用する。
+
+## 困っていること
+
+- `go test`のやり方がいまいちわかっていない。依存関係の解決の仕方が理解に至っていない。
+  - `go test *.go`だと`export_test.go`が解決できない
+  - `go test ./`だと解決できる
+  - `go test ./...`すると`utils`以下がimport cycleで失敗してしまう
+  - `go test ./utils/*`だと`utils`だと問題ない
+    - `go test -cover ./utils/*`でちゃんとカバレッジがどれない
diff --git a/kadai3-2/en-ken/dl-manager.go b/kadai3-2/en-ken/dl-manager.go
new file mode 100644
index 0000000..83d02de
--- /dev/null
+++ b/kadai3-2/en-ken/dl-manager.go
@@ -0,0 +1,124 @@
+package divdl
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/sync/errgroup"
+
+	"github.com/gopherdojo/dojo6/kadai3-2/en-ken/utils"
+	"github.com/pkg/errors"
+)
+
+// DlRange expresses range of Range request
+type DlRange struct {
+	id   int
+	from int64
+	to   int64
+}
+
+var maxRangeSize = int64(1024 * 1024) //1MB
+
+func divideIntoRanges(contentLength int64, numOfDivision int) (numOfRanges int, rngs [][]*DlRange) {
+	rngs = make([][]*DlRange, numOfDivision)
+
+	var rngSize int64
+	if contentLength%int64(numOfDivision) == 0 {
+		rngSize = contentLength / int64(numOfDivision)
+	} else {
+		rngSize = (contentLength + int64(numOfDivision)) / int64(numOfDivision)
+	}
+	if maxRangeSize < rngSize {
+		rngSize = maxRangeSize
+	}
+
+	for j, pos := 0, int64(0); pos < contentLength; j++ {
+		for i := 0; i < numOfDivision && pos < contentLength; i++ {
+			id := j*numOfDivision + i
+			numOfRanges = id + 1
+			// Last range
+			if contentLength-pos < rngSize {
+				rngs[i] = append(rngs[i], &DlRange{
+					id:   id,
+					from: int64(id) * rngSize,
+					to:   contentLength - 1,
+				})
+				pos = contentLength
+				break
+			}
+
+			rngs[i] = append(rngs[i], &DlRange{
+				id:   id,
+				from: int64(id) * rngSize,
+				to:   int64(id+1)*rngSize - 1,
+			})
+			pos += rngSize
+		}
+	}
+	return
+}
+
+// Do manages separately downloading.
+func Do(url string, fileName string, numOfDivision int) error {
+	req, err := utils.NewRequest(url)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	// Range request is not accepted
+	if !req.CanAcceptRangeRequest() {
+		data, err := req.Download()
+		if err != nil {
+			return err
+		}
+
+		return utils.SaveFile(fileName, data)
+	}
+
+	// Range request is accepted
+	n, rngs := divideIntoRanges(req.GetContentLength(), numOfDivision)
+
+	var g errgroup.Group
+	for _, rList := range rngs {
+		rList := rList
+		g.Go(func() error {
+			for _, r := range rList {
+				tmpFileName := createPartialFileName(fileName, r.id)
+
+				// Pass downloading if tmpFileName exists.
+				if fileExists(tmpFileName) {
+					continue
+				}
+
+				data, err := req.DownloadPartially(r.from, r.to)
+				if err != nil {
+					return err
+				}
+				if err := utils.SaveFile(tmpFileName, data); err != nil {
+					return err
+				}
+				fmt.Printf("%v saved\n", tmpFileName)
+			}
+			return nil
+		})
+	}
+
+	if err := g.Wait(); err != nil {
+		return errors.WithStack(err)
+	}
+
+	files := make([]string, 0)
+	for i := 0; i < n; i++ {
+		files = append(files, createPartialFileName(fileName, i))
+	}
+	return utils.MergeFiles(files, fileName)
+}
+
+func createPartialFileName(fileName string, suffix int) string {
+	return fmt.Sprintf("%v.%v", fileName, suffix)
+}
+
+func fileExists(fileName string) bool {
+	_, err := os.Stat(fileName)
+	return err == nil
+}
diff --git a/kadai3-2/en-ken/dl-manager_test.go b/kadai3-2/en-ken/dl-manager_test.go
new file mode 100644
index 0000000..7af553d
--- /dev/null
+++ b/kadai3-2/en-ken/dl-manager_test.go
@@ -0,0 +1,259 @@
+package divdl_test
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+	divdl "github.com/gopherdojo/dojo6/kadai3-2/en-ken"
+)
+
+func TestDivideIntoRanges(t *testing.T) {
+
+	type testCase struct {
+		contentLength int64
+		num           int
+		expected      [][]*divdl.TestRange
+		expectedNum   int
+	}
+
+	cases := []testCase{
+		{
+			contentLength: 100,
+			num:           2,
+			expected: [][]*divdl.TestRange{
+				{
+					&divdl.TestRange{ID: 0, From: 0, To: 49},
+				},
+				{
+					&divdl.TestRange{ID: 1, From: 50, To: 99},
+				},
+			},
+			expectedNum: 2,
+		},
+		{
+			contentLength: 1000,
+			num:           5,
+			expected: [][]*divdl.TestRange{
+				{
+					&divdl.TestRange{ID: 0, From: 0, To: 199},
+				},
+				{
+					&divdl.TestRange{ID: 1, From: 200, To: 399},
+				},
+				{
+					&divdl.TestRange{ID: 2, From: 400, To: 599},
+				},
+				{
+					&divdl.TestRange{ID: 3, From: 600, To: 799},
+				},
+				{
+					&divdl.TestRange{ID: 4, From: 800, To: 999},
+				},
+			},
+			expectedNum: 5,
+		},
+		{
+			contentLength: 1001,
+			num:           5,
+			expected: [][]*divdl.TestRange{
+				{
+					&divdl.TestRange{ID: 0, From: 0, To: 200},
+				},
+				{
+					&divdl.TestRange{ID: 1, From: 201, To: 401},
+				},
+				{
+					&divdl.TestRange{ID: 2, From: 402, To: 602},
+				},
+				{
+					&divdl.TestRange{ID: 3, From: 603, To: 803},
+				},
+				{
+					&divdl.TestRange{ID: 4, From: 804, To: 1000},
+				},
+			},
+			expectedNum: 5,
+		},
+		{
+			contentLength: 1005,
+			num:           5,
+			expected: [][]*divdl.TestRange{
+				{
+					&divdl.TestRange{ID: 0, From: 0, To: 200},
+				},
+				{
+					&divdl.TestRange{ID: 1, From: 201, To: 401},
+				},
+				{
+					&divdl.TestRange{ID: 2, From: 402, To: 602},
+				},
+				{
+					&divdl.TestRange{ID: 3, From: 603, To: 803},
+				},
+				{
+					&divdl.TestRange{ID: 4, From: 804, To: 1004},
+				},
+			},
+			expectedNum: 5,
+		},
+		{
+			contentLength: divdl.MaxRangeSize*8 - 10,
+			num:           5,
+			expected: [][]*divdl.TestRange{
+				{
+					&divdl.TestRange{ID: 0, From: 0, To: divdl.MaxRangeSize - 1},
+					&divdl.TestRange{ID: 5, From: divdl.MaxRangeSize * 5, To: divdl.MaxRangeSize*6 - 1},
+				},
+				{
+					&divdl.TestRange{ID: 1, From: divdl.MaxRangeSize, To: divdl.MaxRangeSize*2 - 1},
+					&divdl.TestRange{ID: 6, From: divdl.MaxRangeSize * 6, To: divdl.MaxRangeSize*7 - 1},
+				},
+				{
+					&divdl.TestRange{ID: 2, From: divdl.MaxRangeSize * 2, To: divdl.MaxRangeSize*3 - 1},
+					&divdl.TestRange{ID: 7, From: divdl.MaxRangeSize * 7, To: divdl.MaxRangeSize*8 - 10 - 1},
+				},
+				{
+					&divdl.TestRange{ID: 3, From: divdl.MaxRangeSize * 3, To: divdl.MaxRangeSize*4 - 1},
+				},
+				{
+					&divdl.TestRange{ID: 4, From: divdl.MaxRangeSize * 4, To: divdl.MaxRangeSize*5 - 1},
+				},
+			},
+			expectedNum: 8,
+		},
+		{
+			contentLength: divdl.MaxRangeSize * 3,
+			num:           2,
+			expected: [][]*divdl.TestRange{
+				{
+					&divdl.TestRange{ID: 0, From: 0, To: divdl.MaxRangeSize - 1},
+					&divdl.TestRange{ID: 2, From: divdl.MaxRangeSize * 2, To: divdl.MaxRangeSize*3 - 1},
+				},
+				{
+					&divdl.TestRange{ID: 1, From: divdl.MaxRangeSize, To: divdl.MaxRangeSize*2 - 1},
+				},
+			},
+			expectedNum: 3,
+		},
+	}
+
+	for i, c := range cases {
+		c := c
+		t.Run(fmt.Sprintf("case %v", i), func(t *testing.T) {
+			n, actual := divdl.DivideIntoRanges(c.contentLength, c.num)
+
+			if !cmp.Equal(actual, c.expected) || n != c.expectedNum {
+				t.Errorf("failed. Diff:\n%v", cmp.Diff(actual, c.expected))
+			}
+		})
+	}
+}
+
+func TestDo(t *testing.T) {
+	type testCase struct {
+		newRequestError bool
+		downloadError   bool
+		canGetRange     bool
+	}
+
+	cases := []testCase{
+		{
+			canGetRange: true,
+		},
+		{
+			canGetRange: false,
+		},
+		{
+			newRequestError: true,
+		},
+		{
+			canGetRange:   true,
+			downloadError: true,
+		},
+		{
+			canGetRange:   false,
+			downloadError: true,
+		},
+	}
+
+	bodyStr := fmt.Sprintf("%v%v%v%v%v",
+		"0000000000",
+		"1111111111",
+		"2222222222",
+		"3333333333",
+		"4444444444",
+	)
+
+	divdl.SetMaxRangeSize(10)
+	tmpDir, _ := ioutil.TempDir("", ".tmp")
+	fileName := filepath.Join(tmpDir, "test.txt")
+
+	for i, c := range cases {
+		c := c
+
+		var testHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			switch r.Method {
+			case "HEAD":
+				if c.newRequestError {
+					w.WriteHeader(http.StatusMethodNotAllowed)
+					fmt.Fprint(w, "")
+					return
+				}
+
+				if c.canGetRange {
+					w.Header().Add("Accept-Ranges", "bytes")
+				}
+				w.Header().Add("Content-Length", fmt.Sprint(len(bodyStr)))
+				fmt.Print(w, "")
+			case "GET":
+				if c.downloadError {
+					w.WriteHeader(http.StatusForbidden)
+					fmt.Fprint(w, "")
+					return
+				}
+
+				rngStr := r.Header.Get("Range")
+				if rngStr != "" {
+					reg := regexp.MustCompile(`\d+`)
+					rngs := reg.FindAllString(rngStr, -1)
+					from, _ := strconv.ParseInt(rngs[0], 10, 0)
+					to, _ := strconv.ParseInt(rngs[1], 10, 0)
+					fmt.Fprint(w, bodyStr[from:to+1])
+				} else {
+					fmt.Fprint(w, bodyStr)
+				}
+			}
+		})
+		ts := httptest.NewServer(testHandler)
+		defer ts.Close()
+
+		t.Run(fmt.Sprintf("case %v", i), func(t *testing.T) {
+			err := divdl.Do(ts.URL, fileName, 3)
+			if err != nil {
+				if !c.newRequestError &&
+					!c.downloadError {
+					t.Errorf("Unexpected result: %v", err)
+				}
+			} else {
+				if c.newRequestError ||
+					c.downloadError {
+					t.Errorf("Unexpected result: newRequestError->%v, downloadError->%v",
+						c.newRequestError, c.downloadError)
+				}
+			}
+
+			actual, _ := ioutil.ReadFile(fileName)
+			if string(actual) != bodyStr {
+				t.Errorf("Downloading file is invalid data: %v", string(actual))
+			}
+
+		})
+	}
+}
diff --git a/kadai3-2/en-ken/dl-mgr/main.go b/kadai3-2/en-ken/dl-mgr/main.go
new file mode 100644
index 0000000..4ec025d
--- /dev/null
+++ b/kadai3-2/en-ken/dl-mgr/main.go
@@ -0,0 +1,43 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"path"
+
+	divdl "github.com/gopherdojo/dojo6/kadai3-2/en-ken"
+
+	"github.com/pkg/errors"
+)
+
+// Do is I/F to divdl.Do
+type Do func(url string, fileName string, numOfDivision int) error
+
+func outputError(err error) {
+	os.Stderr.Write([]byte(fmt.Sprintf("%v", errors.WithStack(err))))
+}
+
+func main() {
+	var (
+		fileName      string
+		numOfDivision int
+	)
+
+	flag.StringVar(&fileName, "o", "[remote-name]", "output file name")
+	flag.IntVar(&numOfDivision, "n", 5, "number of downloading in parallel")
+	flag.Parse()
+	url := flag.Arg(0)
+	// Set remote name as fileName
+	if fileName == "[remote-name]" {
+		fileName = path.Base(url)
+	}
+
+	err := Do(divdl.Do)(url, fileName, numOfDivision)
+	if err != nil {
+		outputError(err)
+		return
+	}
+
+	os.Stdout.Write([]byte("Downloading done.\n"))
+}
diff --git a/kadai3-2/en-ken/export_test.go b/kadai3-2/en-ken/export_test.go
new file mode 100644
index 0000000..f80150d
--- /dev/null
+++ b/kadai3-2/en-ken/export_test.go
@@ -0,0 +1,28 @@
+package divdl
+
+var DivideIntoRanges = func(contentLength int64, numOfDivision int) (int, [][]*TestRange) {
+	n, result := divideIntoRanges(contentLength, numOfDivision)
+	rngs := make([][]*TestRange, numOfDivision)
+	for i, rp := range result {
+		for _, r := range rp {
+			rngs[i] = append(rngs[i], &TestRange{
+				ID:   r.id,
+				From: r.from,
+				To:   r.to,
+			})
+		}
+	}
+	return n, rngs
+}
+
+type TestRange struct {
+	ID   int
+	From int64
+	To   int64
+}
+
+var MaxRangeSize = maxRangeSize
+
+func SetMaxRangeSize(size int64) {
+	maxRangeSize = size
+}
diff --git a/kadai3-2/en-ken/utils/fileutil.go b/kadai3-2/en-ken/utils/fileutil.go
new file mode 100644
index 0000000..138017c
--- /dev/null
+++ b/kadai3-2/en-ken/utils/fileutil.go
@@ -0,0 +1,54 @@
+package utils
+
+import (
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/pkg/errors"
+)
+
+// SaveFile saves data as fileName.
+func SaveFile(fileName string, data []byte) error {
+	file, err := os.Create(fileName)
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("Failed to open %v", fileName))
+	}
+	defer file.Close()
+
+	_, err = file.Write(data)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+	return nil
+}
+
+// MergeFiles merges separeted files.
+func MergeFiles(inputFiles []string, outputFileName string) error {
+
+	fw, err := os.Create(outputFileName)
+	if err != nil {
+		return errors.Wrap(err, fmt.Sprintf("Failed to open output file: %v", outputFileName))
+	}
+	defer fw.Close()
+
+	for _, f := range inputFiles {
+		fr, err := os.Open(f)
+		if err != nil {
+			return errors.Wrap(err, fmt.Sprintf("Failed to open [%v]", f))
+		}
+		defer fr.Close()
+
+		_, err = io.Copy(fw, fr)
+		if err != nil {
+			return errors.Wrap(err, fmt.Sprintf("Failed to write data from %v", f))
+		}
+
+		if err := os.Remove(f); err != nil {
+			return errors.Wrap(err, fmt.Sprintf("Failed to delete %v", f))
+		}
+
+	}
+
+	return nil
+}
diff --git a/kadai3-2/en-ken/utils/fileutil_test.go b/kadai3-2/en-ken/utils/fileutil_test.go
new file mode 100644
index 0000000..b9c5558
--- /dev/null
+++ b/kadai3-2/en-ken/utils/fileutil_test.go
@@ -0,0 +1,76 @@
+package utils_test
+
+import (
+	"io/ioutil"
+	"path/filepath"
+	"testing"
+
+	"github.com/gopherdojo/dojo6/kadai3-2/en-ken/utils"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+var tmpDir string
+
+func TestMain(m *testing.M) {
+	tmpDir, _ = ioutil.TempDir("", ".tmp")
+	m.Run()
+}
+
+func TestSaveFile(t *testing.T) {
+	file := filepath.Join(tmpDir, "test.txt")
+
+	expected := []byte("foo\nbar\nbaz\n")
+	utils.SaveFile(file, expected)
+
+	actual, _ := ioutil.ReadFile(file)
+	if string(actual) != string(expected) {
+		t.Errorf("failed. Diff:\n%v", cmp.Diff(actual, expected))
+	}
+}
+
+func TestMergeFiles(t *testing.T) {
+	strA := "0\n1\n2\n3\n4\n"
+	strB := "5\n6\n7\n8\n9\n"
+	fileInfo := []struct {
+		fileName string
+		data     string
+	}{
+		{
+			fileName: filepath.Join(tmpDir, "merged.txt.0"),
+			data:     strA,
+		},
+		{
+			fileName: filepath.Join(tmpDir, "merged.txt.1"),
+			data:     strB,
+		},
+		{
+			fileName: filepath.Join(tmpDir, "merged.txt.2"),
+			data:     strA,
+		},
+		{
+			fileName: filepath.Join(tmpDir, "merged.txt.3"),
+			data:     strB,
+		},
+	}
+
+	var inputFiles []string
+	var expected string
+	for _, fi := range fileInfo {
+		if err := utils.SaveFile(fi.fileName, []byte(fi.data)); err != nil {
+			t.Errorf("SaveFile failed: %v", err)
+		}
+		inputFiles = append(inputFiles, fi.fileName)
+		expected += fi.data
+	}
+
+	mergedFile := filepath.Join(tmpDir, "merged.txt")
+	if err := utils.MergeFiles(inputFiles, mergedFile); err != nil {
+		t.Errorf("MergeFiles failed: %v", err)
+	}
+
+	actual, _ := ioutil.ReadFile(mergedFile)
+	if string(actual) != expected {
+		t.Errorf("MergeFiles makes invalid data: %v", string(actual))
+	}
+}
diff --git a/kadai3-2/en-ken/utils/request.go b/kadai3-2/en-ken/utils/request.go
new file mode 100644
index 0000000..90e536d
--- /dev/null
+++ b/kadai3-2/en-ken/utils/request.go
@@ -0,0 +1,92 @@
+package utils
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strconv"
+
+	"github.com/pkg/errors"
+)
+
+// Request wraps downloading proceess.
+type Request struct {
+	url                   string
+	contentLength         int64
+	canAcceptRangeRequest bool
+}
+
+// NewRequest is a constructor of Request.
+func NewRequest(url string) (*Request, error) {
+	resp, err := http.Head(url)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	// Header request before downloading
+	acceptRanges := resp.Header.Get("Accept-Ranges")
+	contentLength, err := strconv.ParseInt(resp.Header.Get("Content-Length"), 10, 0)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return &Request{
+		url:                   url,
+		contentLength:         contentLength,
+		canAcceptRangeRequest: acceptRanges == "bytes",
+	}, nil
+}
+
+// DownloadPartially downloads specified part of data from the specified url.
+func (r *Request) DownloadPartially(from int64, to int64) ([]byte, error) {
+	if !r.canAcceptRangeRequest {
+		return nil, fmt.Errorf("This file cannot download with Range")
+	}
+
+	// Set Range Header if Range request is accepted.
+	headers := map[string]string{}
+	headers["Range"] = fmt.Sprintf("bytes=%d-%d", from, to)
+
+	return r.download(headers)
+}
+
+// Download downloads data from the specified url.
+func (r *Request) Download() ([]byte, error) {
+	return r.download(nil)
+}
+
+func (r *Request) download(extraHeaders map[string]string) ([]byte, error) {
+	req, err := http.NewRequest("GET", r.url, nil)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	for k, v := range extraHeaders {
+		req.Header.Add(k, v)
+	}
+
+	resp, err := http.DefaultClient.Do(req)
+	if resp.Status[:1] != "2" {
+		return nil, errors.Errorf("Faild to request: %v", resp.StatusCode)
+	}
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll((resp.Body))
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return body, nil
+}
+
+// CanAcceptRangeRequest is getter of canAcceptRengeRequest
+func (r *Request) CanAcceptRangeRequest() bool {
+	return r.canAcceptRangeRequest
+}
+
+// GetContentLength is getter to content length of data.
+func (r *Request) GetContentLength() int64 {
+	return r.contentLength
+}
diff --git a/kadai3-2/en-ken/utils/request_test.go b/kadai3-2/en-ken/utils/request_test.go
new file mode 100644
index 0000000..6130116
--- /dev/null
+++ b/kadai3-2/en-ken/utils/request_test.go
@@ -0,0 +1,160 @@
+package utils
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gopherdojo/dojo6/kadai3-2/en-ken/utils"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestNewRequest(t *testing.T) {
+	cases := []struct {
+		canHead        bool
+		canAcceptRange bool
+	}{
+		{
+			canHead:        true,
+			canAcceptRange: true,
+		},
+		{
+			canHead:        true,
+			canAcceptRange: false,
+		},
+		{
+			canHead:        false,
+			canAcceptRange: false,
+		},
+	}
+
+	for _, c := range cases {
+		c := c
+
+		body := []byte("success")
+		var testHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			if !c.canHead {
+				w.WriteHeader(http.StatusMethodNotAllowed)
+				return
+			}
+
+			if c.canAcceptRange {
+				w.Header().Add("Accept-Ranges", "bytes")
+			}
+			w.Header().Add("Content-Length", fmt.Sprint(len(body)))
+			fmt.Fprint(w, "")
+		})
+		ts := httptest.NewServer(testHandler)
+		defer ts.Close()
+
+		req, err := utils.NewRequest(ts.URL)
+		if c.canHead {
+			if err != nil {
+				t.Errorf("Unexpected  result: %v", err)
+			}
+		} else {
+			if err == nil {
+				t.Error("Http status error epected.")
+			}
+			return
+		}
+
+		if req == nil {
+			t.Errorf("Unexpected result")
+		}
+		if req.CanAcceptRangeRequest() != c.canAcceptRange {
+			t.Errorf("Unexpected result")
+		}
+	}
+}
+
+func TestDownload(t *testing.T) {
+	bodyStr := fmt.Sprintf("%v%v%v%v%v",
+		"0000000000",
+		"1111111111",
+		"2222222222",
+		"3333333333",
+		"4444444444",
+	)
+
+	cases := []struct {
+		canGet      bool
+		canGetRange bool
+		from        int64
+		to          int64
+		rngStr      string
+		expected    []byte
+	}{
+		{
+			canGet:      true,
+			canGetRange: true,
+			from:        10,
+			to:          19,
+			rngStr:      "bytes=10-19",
+			expected:    []byte(bodyStr[10:20]),
+		},
+		{
+			canGet:      true,
+			canGetRange: false,
+			expected:    []byte(bodyStr),
+		},
+		{
+			canGet: false,
+		},
+	}
+
+	for i, c := range cases {
+		c := c
+		bodyStr := bodyStr
+
+		var testHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			switch r.Method {
+			case "HEAD":
+				if c.canGetRange {
+					w.Header().Add("Accept-Ranges", "bytes")
+				}
+				w.Header().Add("Content-Length", fmt.Sprint(len(bodyStr)))
+				fmt.Print(w, "")
+			case "GET":
+				if c.canGet {
+					rng := r.Header.Get("Range")
+					if rng != "" && rng == c.rngStr {
+						fmt.Fprint(w, bodyStr[c.from:c.to+1])
+					} else {
+						fmt.Fprint(w, bodyStr)
+					}
+				} else {
+					w.WriteHeader(http.StatusNotFound)
+					fmt.Fprint(w, "")
+				}
+			}
+		})
+		ts := httptest.NewServer(testHandler)
+		defer ts.Close()
+
+		t.Run(fmt.Sprintf("case %v", i), func(t *testing.T) {
+			req, _ := utils.NewRequest(ts.URL)
+			var (
+				actual []byte
+				err    error
+			)
+			if req.CanAcceptRangeRequest() {
+				actual, err = req.DownloadPartially(c.from, c.to)
+			} else {
+				actual, err = req.Download()
+			}
+
+			if !c.canGet {
+				if err == nil {
+					t.Error("Unexpected http status")
+				}
+			}
+
+			if !cmp.Equal(c.expected, actual) {
+				t.Errorf("Unexpected response: Diff\n%v", cmp.Diff(c.expected, actual))
+			}
+		})
+	}
+}
diff --git a/kadai4/en-ken/kadai4/export_test.go b/kadai4/en-ken/kadai4/export_test.go
new file mode 100644
index 0000000..f3e1aff
--- /dev/null
+++ b/kadai4/en-ken/kadai4/export_test.go
@@ -0,0 +1,20 @@
+package main
+
+import (
+	"time"
+)
+
+var GetFortune = getFortune
+var Handler = handler
+
+func SetNow(n func() time.Time) {
+	now = n
+}
+
+func SetFortunes(f []string) {
+	fortunes = f
+}
+
+func SetNewEncoder(n NewEncoder) {
+	newEncoder = n
+}
diff --git a/kadai4/en-ken/kadai4/fortune.go b/kadai4/en-ken/kadai4/fortune.go
new file mode 100644
index 0000000..7eebd47
--- /dev/null
+++ b/kadai4/en-ken/kadai4/fortune.go
@@ -0,0 +1,29 @@
+package main
+
+import (
+	"math/rand"
+	"time"
+)
+
+// For testing
+var now = time.Now
+var fortunes []string
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+	fortunes = []string{"大吉", "吉", "中吉", "小吉", "末吉", "凶", "大凶"}
+}
+
+func getFortune() string {
+	i := rand.Int() % len(fortunes)
+	f := fortunes[i]
+
+	t := now()
+	if t.Month() == 1 {
+		if t.Day() >= 1 && t.Day() <= 3 {
+			f = "大吉"
+		}
+	}
+
+	return f
+}
diff --git a/kadai4/en-ken/kadai4/fortune_test.go b/kadai4/en-ken/kadai4/fortune_test.go
new file mode 100644
index 0000000..56b80f1
--- /dev/null
+++ b/kadai4/en-ken/kadai4/fortune_test.go
@@ -0,0 +1,64 @@
+package main_test
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	main "github.com/gopherdojo/dojo6/kadai4/en-ken/kadai4"
+)
+
+func TestGetLuck(t *testing.T) {
+
+	cases := []struct {
+		now      time.Time
+		expected string
+	}{
+		{
+			now:      time.Date(2018, time.December, 31, 0, 0, 0, 0, time.Local),
+			expected: "凶",
+		},
+		{
+			now:      time.Date(2018, time.December, 31, 23, 59, 59, 999, time.Local),
+			expected: "凶",
+		},
+		{
+			now:      time.Date(2019, time.January, 1, 0, 0, 0, 0, time.Local),
+			expected: "大吉",
+		},
+		{
+			now:      time.Date(2019, time.January, 2, 0, 0, 0, 0, time.Local),
+			expected: "大吉",
+		},
+		{
+			now:      time.Date(2019, time.January, 3, 0, 0, 0, 0, time.Local),
+			expected: "大吉",
+		},
+		{
+			now:      time.Date(2018, time.January, 3, 23, 59, 59, 999, time.Local),
+			expected: "大吉",
+		},
+		{
+			now:      time.Date(2019, time.January, 4, 0, 0, 0, 0, time.Local),
+			expected: "凶",
+		},
+	}
+
+	main.SetFortunes([]string{"凶", "凶", "凶"})
+
+	for i, c := range cases {
+		c := c
+		t.Run(
+			fmt.Sprintf("case[%v]", i),
+			func(t *testing.T) {
+				main.SetNow(func() time.Time {
+					return c.now
+				})
+
+				if actual := main.GetFortune(); actual != c.expected {
+					t.Errorf("actual:%v, expected:%v\n", actual, c.expected)
+				}
+			})
+	}
+
+}
diff --git a/kadai4/en-ken/kadai4/main.go b/kadai4/en-ken/kadai4/main.go
new file mode 100644
index 0000000..dd31146
--- /dev/null
+++ b/kadai4/en-ken/kadai4/main.go
@@ -0,0 +1,45 @@
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+)
+
+// Encoder is I/F to json.Encoder
+type Encoder interface {
+	Encode(v interface{}) error
+}
+
+// NewEncoder is I/F to json.NewEncoder
+type NewEncoder func(w io.Writer) Encoder
+
+var newEncoder NewEncoder
+
+func init() {
+	// For testing
+	newEncoder = func(w io.Writer) Encoder {
+		return json.NewEncoder(w)
+	}
+}
+
+func main() {
+	http.HandleFunc("/", handler)
+	http.ListenAndServe(":8080", nil)
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "applicaiton/json; charset=utf-8")
+
+	enc := newEncoder(w)
+
+	resp := &struct {
+		Fortune string `json:"fortune"`
+	}{
+		Fortune: getFortune(),
+	}
+
+	if err := enc.Encode(resp); err != nil {
+		http.Error(w, "Server error", http.StatusInternalServerError)
+	}
+}
diff --git a/kadai4/en-ken/kadai4/main_test.go b/kadai4/en-ken/kadai4/main_test.go
new file mode 100644
index 0000000..1b970bb
--- /dev/null
+++ b/kadai4/en-ken/kadai4/main_test.go
@@ -0,0 +1,79 @@
+package main_test
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	main "github.com/gopherdojo/dojo6/kadai4/en-ken/kadai4"
+)
+
+type data struct {
+	Fortune string `json:"fortune"`
+}
+
+func TestServer(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(main.Handler))
+	defer ts.Close()
+
+	res, err := http.Get(ts.URL)
+	if err != nil {
+		t.Errorf("Response error:%v", err)
+	}
+
+	var d data
+	if err = json.NewDecoder(res.Body).Decode(&d); err != nil {
+		t.Errorf("Data format error:%v", err)
+	}
+}
+
+type EncoderMock struct {
+}
+
+func NewEncoderMock(w io.Writer) main.Encoder {
+	return &EncoderMock{}
+}
+
+func (enc *EncoderMock) Encode(v interface{}) error {
+	return fmt.Errorf("Internal server error")
+}
+
+func TestServerInternalServerError(t *testing.T) {
+	main.SetNewEncoder(NewEncoderMock)
+	defer main.SetNewEncoder(main.NewEncoder(func(w io.Writer) main.Encoder {
+		return json.NewEncoder(w)
+	}))
+
+	ts := httptest.NewServer(http.HandlerFunc(main.Handler))
+	defer ts.Close()
+
+	res, _ := http.Get(ts.URL)
+	if res.StatusCode != 500 {
+		t.Errorf("Response code error:%v", res.StatusCode)
+	}
+
+}
+
+func TestHandler(t *testing.T) {
+	r := httptest.NewRequest("GET", "/", nil)
+	w := httptest.NewRecorder()
+	main.SetFortunes([]string{"大凶"})
+
+	main.Handler(w, r)
+
+	if w.Code != 200 {
+		t.Errorf("Invalid code: %v", w.Code)
+	}
+	if w.Header().Get("Content-Type") != "applicaiton/json; charset=utf-8" {
+		t.Errorf("Insufficient headers: %v", w.Header())
+	}
+	body := w.Body
+	dec := json.NewDecoder(body)
+	var d data
+	if err := dec.Decode(&d); err != nil || d.Fortune != "大凶" {
+		t.Errorf("Failed to decode: %v", err)
+	}
+}
diff --git a/kadai4/en-ken/reame.md b/kadai4/en-ken/reame.md
new file mode 100644
index 0000000..6cd0128
--- /dev/null
+++ b/kadai4/en-ken/reame.md
@@ -0,0 +1,14 @@
+# 課題4
+
+おみくじ API を作りましょう
+
+- JSON形式でおみくじの結果を返す
+- 正月 (1/1-1/3) だけ大吉にする
+- ハンドラのテストを書いてみる
+
+## 使い方
+
+```go
+go get github.com/gopherdojo/dojo6/kadai4/en-ken/kadai4
+kadai4
+```