diff --git a/kadai4/int128/README.md b/kadai4/int128/README.md
new file mode 100644
index 0000000..189c2df
--- /dev/null
+++ b/kadai4/int128/README.md
@@ -0,0 +1,63 @@
+# kadai4
+
+> - JSON形式でおみくじの結果を返す
+> - 結果は毎回ランダムに変わるようにする
+> - 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
+
+## 実行例
+
+```
+% go run main.go
+2018/07/09 10:24:36 Listening on :8000
+2018/07/09 10:24:57 GET /
+2018/07/09 10:25:09 GET /api/omikuji
+2018/07/09 10:25:14 GET /api/omikuji
+2018/07/09 10:25:16 GET /api/omikuji
+```
+
+```
+% curl -v http://localhost:8000/api/omikuji
+> GET /api/omikuji HTTP/1.1
+> Host: localhost:8000
+> User-Agent: curl/7.54.0
+> Accept: */*
+>
+< HTTP/1.1 200 OK
+< Content-Type: application/json
+< Date: Mon, 09 Jul 2018 01:25:09 GMT
+< Content-Length: 32
+<
+{"description":"凶","value":1}
+```
+
+```
+% curl -v http://localhost:8000/api/omikuji
+> GET /api/omikuji HTTP/1.1
+> Host: localhost:8000
+> User-Agent: curl/7.54.0
+> Accept: */*
+>
+< HTTP/1.1 200 OK
+< Content-Type: application/json
+< Date: Mon, 09 Jul 2018 01:25:16 GMT
+< Content-Length: 35
+<
+{"description":"中吉","value":3}
+```
+
+```
+% curl -v http://localhost:8000/
+> GET / HTTP/1.1
+> Host: localhost:8000
+> User-Agent: curl/7.54.0
+> Accept: */*
+>
+< HTTP/1.1 404 Not Found
+< Content-Type: text/plain; charset=utf-8
+< X-Content-Type-Options: nosniff
+< Date: Mon, 09 Jul 2018 01:24:57 GMT
+< Content-Length: 19
+<
+404 page not found
+```
diff --git a/kadai4/int128/main.go b/kadai4/int128/main.go
new file mode 100644
index 0000000..462a720
--- /dev/null
+++ b/kadai4/int128/main.go
@@ -0,0 +1,24 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"os"
+
+	"github.com/gopherdojo/dojo2/kadai4/int128/routes"
+)
+
+func main() {
+	addr := ":8000"
+	if port := os.Getenv("PORT"); port != "" {
+		addr = ":" + port
+	}
+	s := http.Server{
+		Addr:    addr,
+		Handler: routes.New(),
+	}
+	log.Printf("Listening on %s", s.Addr)
+	if err := s.ListenAndServe(); err != nil {
+		log.Fatal(err)
+	}
+}
diff --git a/kadai4/int128/omikuji/service.go b/kadai4/int128/omikuji/service.go
new file mode 100644
index 0000000..11b2d05
--- /dev/null
+++ b/kadai4/int128/omikuji/service.go
@@ -0,0 +1,57 @@
+package omikuji
+
+import (
+	"math/rand"
+	"time"
+)
+
+// Service provides omikuji.
+type Service interface {
+	Hiku() Omikuji
+}
+
+// New returns a new Service.
+func New() Service {
+	return &DefaultService{
+		random: rand.New(rand.NewSource(time.Now().UnixNano())),
+	}
+}
+
+// DefaultService is a default implementation of Service.
+type DefaultService struct {
+	random *rand.Rand       // Random generator
+	time   func() time.Time // Time provider (optional)
+}
+
+// Hiku peforms おみくじを引く.
+// If the current date is shogatsu, it always returns the DaiKichi.
+func (s *DefaultService) Hiku() Omikuji {
+	if s.isShogatsu() {
+		return DaiKichi
+	}
+	n := s.random.Intn(6)
+	switch n {
+	default:
+		return Kyo
+	case 2, 3:
+		return ShoKichi
+	case 4:
+		return ChuKichi
+	case 5:
+		return DaiKichi
+	}
+}
+
+func (s *DefaultService) isShogatsu() bool {
+	now := time.Now()
+	if s.time != nil {
+		now = s.time()
+	}
+	if now.Month() == time.January {
+		switch now.Day() {
+		case 1, 2, 3:
+			return true
+		}
+	}
+	return false
+}
diff --git a/kadai4/int128/omikuji/service_test.go b/kadai4/int128/omikuji/service_test.go
new file mode 100644
index 0000000..30a686d
--- /dev/null
+++ b/kadai4/int128/omikuji/service_test.go
@@ -0,0 +1,39 @@
+package omikuji
+
+import (
+	"math/rand"
+	"testing"
+	"time"
+)
+
+func TestDefaultService_IsShogatsu(t *testing.T) {
+	tokyoTime, err := time.LoadLocation("Asia/Tokyo")
+	if err != nil {
+		t.Fatal(err)
+	}
+	matrix := []struct {
+		now      time.Time
+		expected bool
+	}{
+		{time.Date(2017, 12, 31, 0, 0, 0, 0, tokyoTime), false},
+		{time.Date(2017, 12, 31, 23, 59, 59, 0, tokyoTime), false},
+		{time.Date(2018, 1, 1, 0, 0, 0, 0, tokyoTime), true},
+		{time.Date(2018, 1, 2, 0, 0, 0, 0, tokyoTime), true},
+		{time.Date(2018, 1, 3, 0, 0, 0, 0, tokyoTime), true},
+		{time.Date(2018, 1, 3, 23, 59, 59, 0, tokyoTime), true},
+		{time.Date(2018, 1, 4, 0, 0, 0, 0, tokyoTime), false},
+		{time.Date(2018, 2, 1, 0, 0, 0, 0, tokyoTime), false},
+	}
+	for _, m := range matrix {
+		t.Run(m.now.String(), func(t *testing.T) {
+			s := &DefaultService{
+				random: rand.New(rand.NewSource(0)),
+				time:   func() time.Time { return m.now },
+			}
+			actual := s.isShogatsu()
+			if m.expected != actual {
+				t.Errorf("shogatsu wants %v but %v", m.expected, actual)
+			}
+		})
+	}
+}
diff --git a/kadai4/int128/omikuji/types.go b/kadai4/int128/omikuji/types.go
new file mode 100644
index 0000000..90ab5c0
--- /dev/null
+++ b/kadai4/int128/omikuji/types.go
@@ -0,0 +1,31 @@
+package omikuji
+
+// Omikuji represents a result of omikuji.
+type Omikuji int
+
+const (
+	_ Omikuji = iota
+	// Kyo means 凶.
+	Kyo
+	// ShoKichi means 小吉.
+	ShoKichi
+	// ChuKichi means 中吉.
+	ChuKichi
+	// DaiKichi means 大吉.
+	DaiKichi
+)
+
+func (o Omikuji) String() string {
+	switch o {
+	case Kyo:
+		return "凶"
+	case ShoKichi:
+		return "小吉"
+	case ChuKichi:
+		return "中吉"
+	case DaiKichi:
+		return "大吉"
+	default:
+		return ""
+	}
+}
diff --git a/kadai4/int128/routes/omikuji.go b/kadai4/int128/routes/omikuji.go
new file mode 100644
index 0000000..36a4ea8
--- /dev/null
+++ b/kadai4/int128/routes/omikuji.go
@@ -0,0 +1,36 @@
+package routes
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/gopherdojo/dojo2/kadai4/int128/omikuji"
+)
+
+// OmikujiHandler is a HTTP handler for GET omikuji
+type OmikujiHandler struct {
+	service omikuji.Service
+}
+
+// OmikujiGetResponse is a GET response of OmikujiHandler.
+type OmikujiGetResponse struct {
+	Description string `json:"description"`
+	Value       int    `json:"value"`
+}
+
+func (h *OmikujiHandler) ServeHTTP(w http.ResponseWriter, req *http.Request) {
+	defer req.Body.Close()
+	switch req.Method {
+	case "GET":
+		w.Header().Add("Content-Type", "application/json")
+		o := h.service.Hiku()
+		e := json.NewEncoder(w)
+		res := OmikujiGetResponse{o.String(), int(o)}
+		if err := e.Encode(res); err != nil {
+			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+			return
+		}
+	default:
+		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
+	}
+}
diff --git a/kadai4/int128/routes/omikuji_test.go b/kadai4/int128/routes/omikuji_test.go
new file mode 100644
index 0000000..3e168f9
--- /dev/null
+++ b/kadai4/int128/routes/omikuji_test.go
@@ -0,0 +1,39 @@
+package routes
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gopherdojo/dojo2/kadai4/int128/omikuji"
+)
+
+func TestOmikujiHandler_GET(t *testing.T) {
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest("GET", "/api/omikuji", nil)
+	h := &OmikujiHandler{omikuji.New()}
+	h.ServeHTTP(w, r)
+	res := w.Result()
+	defer res.Body.Close()
+	if http.StatusOK != res.StatusCode {
+		t.Fatalf("res.StatusCode wants %d but %d", http.StatusOK, res.StatusCode)
+	}
+	d := json.NewDecoder(res.Body)
+	var json OmikujiGetResponse
+	if err := d.Decode(&json); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestOmikujiHandler_POST(t *testing.T) {
+	w := httptest.NewRecorder()
+	r := httptest.NewRequest("POST", "/api/omikuji", nil)
+	h := &OmikujiHandler{omikuji.New()}
+	h.ServeHTTP(w, r)
+	res := w.Result()
+	defer res.Body.Close()
+	if http.StatusMethodNotAllowed != res.StatusCode {
+		t.Fatalf("res.StatusCode wants %d but %d", http.StatusMethodNotAllowed, res.StatusCode)
+	}
+}
diff --git a/kadai4/int128/routes/routes.go b/kadai4/int128/routes/routes.go
new file mode 100644
index 0000000..485837e
--- /dev/null
+++ b/kadai4/int128/routes/routes.go
@@ -0,0 +1,22 @@
+package routes
+
+import (
+	"log"
+	"net/http"
+
+	"github.com/gopherdojo/dojo2/kadai4/int128/omikuji"
+)
+
+// New returns a handler with application routes.
+func New() http.Handler {
+	m := http.NewServeMux()
+	m.Handle("/api/omikuji", &OmikujiHandler{omikuji.New()})
+	return withLogging(m)
+}
+
+func withLogging(h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		log.Printf("%s %s", r.Method, r.RequestURI)
+		h.ServeHTTP(w, r)
+	})
+}