diff --git a/agent/state.go b/agent/state.go
index 27d8c15..ce9e9c4 100644
--- a/agent/state.go
+++ b/agent/state.go
@@ -69,3 +69,30 @@ func (a *Agent) validCharacter() bool {
 		len(a.Character.Hobbies) != 0 &&
 		len(a.Character.MusicTaste) != 0
 }
+
+const fmtT = `=====================
+Name: %s
+Age: %d
+Occupation: %s
+Now doing: %s
+Doing next: %s
+Done history: %v
+Memories: %v
+Hobbies: %v
+Music taste: %v
+=====================`
+
+func (a *Agent) String() string {
+	return fmt.Sprintf(
+		fmtT,
+		a.Character.Name,
+		a.Character.Age,
+		a.Character.Occupation,
+		a.Character.NowDoing,
+		a.Character.DoingNext,
+		a.Character.DoneHistory,
+		a.Character.Memories,
+		a.Character.Hobbies,
+		a.Character.MusicTaste,
+	)
+}
diff --git a/agent/state_test.go b/agent/state_test.go
index 1df175c..f8fa0e7 100644
--- a/agent/state_test.go
+++ b/agent/state_test.go
@@ -27,7 +27,7 @@ var _ = Describe("Agent test", func() {
 			Expect(agent.Character.Memories).ToNot(BeEmpty())
 			Expect(agent.Character.Hobbies).ToNot(BeEmpty())
 			Expect(agent.Character.MusicTaste).ToNot(BeEmpty())
-			fmt.Printf("%+v\n", agent.Character)
+			fmt.Println(agent.String())
 		})
 		It("detect an invalid character", func() {
 			_, err := New(WithRandomIdentity())
@@ -49,7 +49,7 @@ var _ = Describe("Agent test", func() {
 			Expect(agent.Character.Memories).ToNot(BeEmpty())
 			Expect(agent.Character.Hobbies).ToNot(BeEmpty())
 			Expect(agent.Character.MusicTaste).ToNot(BeEmpty())
-			fmt.Printf("%+v\n", agent.Character)
+			fmt.Println(agent.String())
 		})
 	})
 })