diff --git a/kadai4/yoheimiyamoto/README.md b/kadai4/yoheimiyamoto/README.md
new file mode 100644
index 0000000..7eaa6be
--- /dev/null
+++ b/kadai4/yoheimiyamoto/README.md
@@ -0,0 +1,4 @@
+## 概要
+* 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
diff --git a/kadai4/yoheimiyamoto/main.go b/kadai4/yoheimiyamoto/main.go
new file mode 100644
index 0000000..248a593
--- /dev/null
+++ b/kadai4/yoheimiyamoto/main.go
@@ -0,0 +1,12 @@
+package main
+
+import (
+	"net/http"
+
+	"github.com/YoheiMiyamoto/dojo4/kadai4/yoheimiyamoto/omikuji"
+)
+
+func main() {
+	http.HandleFunc("/", omikuji.Handler)
+	http.ListenAndServe(":8080", nil)
+}
diff --git a/kadai4/yoheimiyamoto/omikuji/client.go b/kadai4/yoheimiyamoto/omikuji/client.go
new file mode 100644
index 0000000..e0ab4f8
--- /dev/null
+++ b/kadai4/yoheimiyamoto/omikuji/client.go
@@ -0,0 +1,46 @@
+package omikuji
+
+import (
+	"math/rand"
+	"time"
+)
+
+type client struct {
+	now now
+}
+
+type now func() time.Time
+
+func NewClient() *client {
+	return &client{
+		now(func() time.Time {
+			return time.Now()
+		}),
+	}
+}
+
+func (c *client) play() *Result {
+	t := getType(c.now())
+	return &Result{t}
+}
+
+// 吉凶を取得（大吉,中吉,小吉,凶,大凶）
+func getType(now time.Time) string {
+	// 三が日は大吉にする
+	if now.Month() == 1 {
+		if now.Day() == 1 || now.Day() == 2 || now.Day() == 3 {
+			return "大吉"
+		}
+	}
+
+	// 三が日以外はランダム
+	types := []string{
+		"大吉",
+		"中吉",
+		"小吉",
+		"凶",
+		"大凶",
+	}
+	rand.Seed(time.Now().UnixNano())
+	return types[rand.Intn(len(types))]
+}
diff --git a/kadai4/yoheimiyamoto/omikuji/client_test.go b/kadai4/yoheimiyamoto/omikuji/client_test.go
new file mode 100644
index 0000000..4442e51
--- /dev/null
+++ b/kadai4/yoheimiyamoto/omikuji/client_test.go
@@ -0,0 +1,32 @@
+package omikuji
+
+import (
+	"testing"
+	"time"
+)
+
+func TestGetType(t *testing.T) {
+	t.Run("", func(t *testing.T) {
+		testGetType(t, time.Date(2019, 1, 1, 0, 0, 0, 0, time.Local), "大吉")
+	})
+}
+
+// TestGetTypeのテストヘルパー
+func testGetType(t *testing.T, in time.Time, expected string) {
+	t.Helper()
+	r := getType(in)
+	if r != expected {
+		t.Errorf("expected: %s, actual: %s", expected, r)
+	}
+}
+
+func TestPlay(t *testing.T) {
+	c := &client{
+		now(func() time.Time { return time.Date(2019, 1, 1, 0, 0, 0, 0, time.Local) }),
+	}
+	actual := *c.play()
+	expected := Result{"大吉"}
+	if actual != expected {
+		t.Fatalf("actual: %v, expected: %v", actual, expected)
+	}
+}
diff --git a/kadai4/yoheimiyamoto/omikuji/handler.go b/kadai4/yoheimiyamoto/omikuji/handler.go
new file mode 100644
index 0000000..5f2da26
--- /dev/null
+++ b/kadai4/yoheimiyamoto/omikuji/handler.go
@@ -0,0 +1,17 @@
+package omikuji
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+)
+
+func Handler(w http.ResponseWriter, r *http.Request) {
+	c := NewClient()
+	result := c.play()
+	err := json.NewEncoder(w).Encode(result)
+	if err != nil {
+		log.Fatal(err)
+		return
+	}
+}
diff --git a/kadai4/yoheimiyamoto/omikuji/handler_test.go b/kadai4/yoheimiyamoto/omikuji/handler_test.go
new file mode 100644
index 0000000..b3855d4
--- /dev/null
+++ b/kadai4/yoheimiyamoto/omikuji/handler_test.go
@@ -0,0 +1,35 @@
+package omikuji
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func TestHandler(t *testing.T) {
+	// どうにかして、現在時刻を三が日に変更する必要がある
+
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest("GET", "/", nil)
+	Handler(w, r)
+	rw := w.Result()
+	defer rw.Body.Close()
+	if rw.StatusCode != http.StatusOK {
+		t.Fatal("unexpected status code")
+	}
+	b, err := ioutil.ReadAll(rw.Body)
+	if err != nil {
+		t.Fatal("unexpected error")
+	}
+	var actual Result
+	err = json.Unmarshal(b, &actual)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expected := Result{"大吉"}
+	if actual != expected {
+		t.Fatalf("actual: %v, expected: %v", actual, expected)
+	}
+}
diff --git a/kadai4/yoheimiyamoto/omikuji/result.go b/kadai4/yoheimiyamoto/omikuji/result.go
new file mode 100644
index 0000000..70a2616
--- /dev/null
+++ b/kadai4/yoheimiyamoto/omikuji/result.go
@@ -0,0 +1,7 @@
+package omikuji
+
+// Result ...
+type Result struct {
+	Type string `json:"type"` // 吉凶（大吉,中吉,小吉,凶,大凶）
+	// Message string `json:"message`
+}