diff --git a/kadai4/translucens/README.md b/kadai4/translucens/README.md
new file mode 100644
index 0000000..a5df0ec
--- /dev/null
+++ b/kadai4/translucens/README.md
@@ -0,0 +1,22 @@
+# 課題4
+
+おみくじAPIを作ってみよう。
+
+* JSON形式でおみくじの結果を返す
+  * `result`に結果が入るようにしました
+* 正月（1/1-1/3）だけ大吉にする
+  * 正月の前後で境界値試験を記述しました
+* ハンドラのテストを書いてみる
+  * `TestHTTPHandler`に記述しました
+
+使い方
+
+```sh
+$ go run omikujiserver.go
+# In another terminal
+$ curl --silent localhost:8080 | jq .
+{
+  "result": "吉",
+  "date": "2018-05-25 02:35:02.0177204 +0900 DST m=+106.863404001"
+}
+```
diff --git a/kadai4/translucens/omikuji/omikuji.go b/kadai4/translucens/omikuji/omikuji.go
new file mode 100644
index 0000000..6e71747
--- /dev/null
+++ b/kadai4/translucens/omikuji/omikuji.go
@@ -0,0 +1,61 @@
+package omikuji
+
+import (
+	"encoding/json"
+	"log"
+	"math/rand"
+	"net/http"
+	"time"
+)
+
+var nowFunc = time.Now
+
+func init() {
+	rand.Seed(time.Now().UnixNano())
+}
+
+// Response is the type of omikuji result
+type Response struct {
+	Result string `json:"result"`
+	Date   string `json:"date"`
+}
+
+// HTTPHandler writes omikuji into HTTP response
+func HTTPHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	res := Response{
+		Result: omikuji(),
+		Date:   nowFunc().String(),
+	}
+
+	if err := json.NewEncoder(w).Encode(res); err != nil {
+		log.Println("Error in JSON Encoder: ", err)
+	}
+}
+
+func omikuji() string {
+
+	now := nowFunc()
+
+	if 1 <= now.YearDay() && now.YearDay() <= 3 {
+		return "大吉！"
+	}
+
+	i := rand.Intn(100)
+	switch {
+	case i < 17:
+		return "大吉"
+	case i < 17+30:
+		return "凶"
+	case i < 17+30+36:
+		return "吉"
+	case i < 17+30+36+6:
+		return "末吉"
+	case i < 17+30+36+6+3:
+		return "末小吉"
+	case i < 17+30+36+6+3+4:
+		return "半吉"
+	default:
+		return "小吉"
+	}
+}
diff --git a/kadai4/translucens/omikuji/omikuji_test.go b/kadai4/translucens/omikuji/omikuji_test.go
new file mode 100644
index 0000000..bad28dd
--- /dev/null
+++ b/kadai4/translucens/omikuji/omikuji_test.go
@@ -0,0 +1,129 @@
+package omikuji
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+)
+
+func Test_omikujiNewYear(t *testing.T) {
+
+	nowFunc = func() time.Time {
+		return time.Date(2018, time.January, 1, 0, 0, 0, 0, time.Local)
+	}
+
+	result := omikuji()
+	if result != "大吉！" {
+		t.Errorf("omikuji() = %s", result)
+	}
+
+}
+
+func Test_omikujiNewYear2(t *testing.T) {
+
+	nowFunc = func() time.Time {
+		return time.Date(2018, time.January, 3, 23, 59, 59, 0, time.Local)
+	}
+
+	result := omikuji()
+	if result != "大吉！" {
+		t.Errorf("omikuji() = %s", result)
+	}
+
+}
+
+func Test_omikujiNotNewYear(t *testing.T) {
+
+	nowFunc = func() time.Time {
+		return time.Date(2018, time.January, 4, 0, 0, 0, 0, time.Local)
+	}
+
+	switch result := omikuji(); result {
+	case "大吉", "凶", "吉", "末吉", "末小吉", "半吉", "小吉":
+		t.Logf("omikuji() = %s", result)
+	default:
+		t.Errorf("omikuji() = %s", result)
+	}
+}
+
+func Test_omikujiNotNewYear2(t *testing.T) {
+
+	nowFunc = func() time.Time {
+		return time.Date(2017, time.December, 31, 23, 59, 59, 0, time.Local)
+	}
+
+	switch result := omikuji(); result {
+	case "大吉", "凶", "吉", "末吉", "末小吉", "半吉", "小吉":
+		t.Logf("omikuji() = %s", result)
+	default:
+		t.Errorf("omikuji() = %s", result)
+	}
+}
+
+func TestHTTPHandler(t *testing.T) {
+
+	w := httptest.NewRecorder()
+	req := httptest.NewRequest("GET", "/", nil)
+
+	HTTPHandler(w, req)
+	result := w.Result()
+	defer result.Body.Close()
+
+	if result.StatusCode != http.StatusOK {
+		t.Fatalf("Unexpected Status Code: %d", result.StatusCode)
+	}
+
+	body, err := ioutil.ReadAll(result.Body)
+	if err != nil {
+		t.Fatal("Cannot read response body ", err)
+	}
+
+	decoder := json.NewDecoder(bytes.NewBuffer(body))
+	var res Response
+	err = decoder.Decode(&res)
+	if err != nil {
+		t.Fatal("Decode error: ", err)
+	}
+
+	switch res.Result {
+	case "大吉", "凶", "吉", "末吉", "末小吉", "半吉", "小吉":
+		t.Logf("result = %s", res)
+	default:
+		t.Errorf("result = %s", res)
+	}
+}
+
+func testResultCount(t *testing.T, actualCount, expectedCount int) {
+	t.Helper()
+
+	diff := 100
+
+	if actualCount < expectedCount-diff {
+		t.Errorf("The actual number is too small, actual: %d, expected: %d", actualCount, expectedCount)
+	} else if expectedCount+diff < actualCount {
+		t.Errorf("The actual number is too large, actual: %d, expected: %d", actualCount, expectedCount)
+	} else {
+		t.Logf("The actual and expected numbers are %d, %d", actualCount, expectedCount)
+	}
+}
+
+func Test_omikuji10000times(t *testing.T) {
+
+	resultCount := make(map[string]int)
+
+	for i := 0; i < 10000; i++ {
+		resultCount[omikuji()]++
+	}
+
+	testResultCount(t, resultCount["大吉"], 1700)
+	testResultCount(t, resultCount["凶"], 3000)
+	testResultCount(t, resultCount["吉"], 3600)
+	testResultCount(t, resultCount["末吉"], 600)
+	testResultCount(t, resultCount["末小吉"], 300)
+	testResultCount(t, resultCount["半吉"], 400)
+	testResultCount(t, resultCount["小吉"], 300)
+}
diff --git a/kadai4/translucens/omikujiserver.go b/kadai4/translucens/omikujiserver.go
new file mode 100644
index 0000000..13f4c61
--- /dev/null
+++ b/kadai4/translucens/omikujiserver.go
@@ -0,0 +1,15 @@
+package main
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/translucens/dojo1/kadai4/translucens/omikuji"
+)
+
+func main() {
+	http.HandleFunc("/", omikuji.HTTPHandler)
+	if err := http.ListenAndServe(":8080", nil); err != nil {
+		log.Println(err)
+	}
+}