diff --git a/kadai3-2/yoheimiyamoto/downloader/client.go b/kadai3-2/yoheimiyamoto/downloader/client.go
new file mode 100644
index 0000000..e274b25
--- /dev/null
+++ b/kadai3-2/yoheimiyamoto/downloader/client.go
@@ -0,0 +1,150 @@
+package downloader
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"strconv"
+
+	"golang.org/x/sync/errgroup"
+)
+
+// Client ...
+type Client struct {
+	*http.Client
+	url string
+}
+
+// NewClient ...
+func NewClient(url string) *Client {
+	return &Client{new(http.Client), url}
+}
+
+// Download ...
+func (c *Client) Download(ctx context.Context) error {
+	l, err := c.contentLength()
+	if err != nil {
+		return err
+	}
+
+	fmt.Fprintf(os.Stdout, "contentLength: %d\n", l)
+
+	eg, ctx := errgroup.WithContext(ctx)
+
+	ps := newRangeProperties(l)
+	fmt.Fprintf(os.Stdout, "ps: %d\n", len(ps))
+
+	for _, p := range ps {
+		p := p
+		eg.Go(func() error {
+			return c.rangeDownload(ctx, p)
+		})
+	}
+
+	if err := eg.Wait(); err != nil {
+		return err
+	}
+
+	defer removeFiles(ps)
+
+	src := make([]string, len(ps))
+	for i, p := range ps {
+		src[i] = p.path
+	}
+	err = mergeFiles(src, "output.jpg")
+	if err != nil {
+		return nil
+	}
+	return nil
+}
+
+// contentLengthを取得
+func (c *Client) contentLength() (int, error) {
+	res, err := c.Head(c.url)
+	if err != nil {
+		return 0, err
+	}
+	return strconv.Atoi(res.Header.Get("Content-Length"))
+}
+
+// ファイルの分割ダウンロード
+// start -> 開始のbyte
+// end -> 終了のbyte
+// dst -> ダウンロード先のファイル名
+func (c *Client) rangeDownload(ctx context.Context, r *rangeProperty) error {
+	errCh := make(chan error, 1)
+
+	go func() {
+		req, _ := http.NewRequest("GET", c.url, nil)
+		req.Header.Set("Authorization", "Bearer access-token")
+		req.Header.Set("Range", fmt.Sprintf("bytes=%d-%d", r.start, r.end))
+
+		res, err := c.Do(req)
+		if err != nil {
+			errCh <- err
+			return
+		}
+		defer res.Body.Close()
+
+		f, err := os.Create(r.path)
+		if err != nil {
+			errCh <- err
+			return
+		}
+		defer f.Close()
+
+		_, err = io.Copy(f, res.Body)
+		if err != nil {
+			errCh <- err
+			return
+		}
+		errCh <- nil
+	}()
+
+	select {
+	case err := <-errCh:
+		if err != nil {
+			return err
+		}
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+
+	return nil
+}
+
+// ダウンロードした分割ファイルのマージ
+// src -> 元の分割ファイル名
+// dst -> マージ先のファイル名
+func mergeFiles(src []string, dst string) error {
+	f, err := os.Create(dst)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+	for _, s := range src {
+		_f, err := os.Open(s)
+		if err != nil {
+			return err
+		}
+		_, err = io.Copy(f, _f)
+		if err != nil {
+			return err
+		}
+		_f.Close()
+	}
+	return nil
+}
+
+// 一時保存ファイルの全削除
+func removeFiles(ps []*rangeProperty) error {
+	for _, p := range ps {
+		err := os.Remove(p.path)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/kadai3-2/yoheimiyamoto/downloader/client_test.go b/kadai3-2/yoheimiyamoto/downloader/client_test.go
new file mode 100644
index 0000000..8a03437
--- /dev/null
+++ b/kadai3-2/yoheimiyamoto/downloader/client_test.go
@@ -0,0 +1,41 @@
+package downloader
+
+import "testing"
+
+const URL = "https://images.pexels.com/photos/248304/pexels-photo-248304.jpeg"
+
+func TestContentLength(t *testing.T) {
+	c := NewClient(URL)
+	l, err := c.contentLength()
+	if err != nil {
+		t.Error(err)
+	}
+	expect := 6480509
+	if l != expect {
+		t.Errorf("expect: %d, actual: %d", expect, l)
+	}
+}
+
+func TestNewRangeProperties(t *testing.T) {
+	// ps := newRangeProperties(40001)
+	// t.Logf("%v", ps[0])
+	// t.Logf("%v", ps[1])
+	// t.Logf("%v", ps[2])
+	// t.Logf("%v", ps[3])
+	// t.Logf("%v", ps[4])
+}
+
+func TestRangeDownload(t *testing.T) {
+	// c := NewClient(URL)
+	// c.rangeDownload("1.jpg", 0, 5000)
+	// c.rangeDownload("2.jpg", 5001, 6480509)
+}
+
+func TestMergeFiles(t *testing.T) {
+	// c := NewClient(URL)
+	// src := []string{"1.jpg", "2.jpg"}
+	// err := c.mergeFiles(src, "image.jpg")
+	// if err != nil {
+	// 	t.Error(err)
+	// }
+}
diff --git a/kadai3-2/yoheimiyamoto/downloader/image.jpg b/kadai3-2/yoheimiyamoto/downloader/image.jpg
new file mode 100644
index 0000000..e69de29
diff --git a/kadai3-2/yoheimiyamoto/downloader/range_property.go b/kadai3-2/yoheimiyamoto/downloader/range_property.go
new file mode 100644
index 0000000..276eb18
--- /dev/null
+++ b/kadai3-2/yoheimiyamoto/downloader/range_property.go
@@ -0,0 +1,48 @@
+package downloader
+
+import (
+	"fmt"
+	"math"
+)
+
+type rangeProperty struct {
+	path  string // 一時保存先のファイル名
+	start int    // 開始のバイト数
+	end   int    // 終了のバイト数
+}
+
+// rangeDownloadの引数として必要なrangePropertyを生成
+func newRangeProperties(contentLength int) []*rangeProperty {
+	num := 1000000
+
+	maxIndex := int(math.Ceil(float64(contentLength) / float64(num)))
+
+	f := func(i int) *rangeProperty {
+		start := 0
+		if i != 0 {
+			start = i*num + 1
+		}
+		end := (i + 1) * num
+		if end > contentLength {
+			end = contentLength
+		}
+		return &rangeProperty{
+			path:  fmt.Sprintf("file%d.jpg", i),
+			start: start,
+			end:   end,
+		}
+	}
+
+	var out []*rangeProperty
+
+	for i := 0; i < maxIndex; i++ {
+		start := i + num
+		end := start + num
+		if end > contentLength {
+			end = contentLength
+		}
+		out = append(out, f(i))
+	}
+
+	return out
+}
diff --git a/kadai3-2/yoheimiyamoto/main.go b/kadai3-2/yoheimiyamoto/main.go
new file mode 100644
index 0000000..051925d
--- /dev/null
+++ b/kadai3-2/yoheimiyamoto/main.go
@@ -0,0 +1,17 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/YoheiMiyamoto/dojo4/kadai3-2/yoheimiyamoto/downloader"
+)
+
+func main() {
+	c := downloader.NewClient("https://images.pexels.com/photos/248304/pexels-photo-248304.jpeg")
+	err := c.Download(context.Background())
+	if err != nil {
+		fmt.Fprintln(os.Stdout, err.Error())
+	}
+}