public void Init(int n)
    {
        state = (STATE)Enum.ToObject(typeof(STATE), n);
        switch (state)
        {
        case STATE.KEY:
            key = this.gameObject.GetComponent <ItemKey> ();
            key.Init();
            Debug.Log("Key Inited");
            break;

        case STATE.NOISY:
            noisy = this.gameObject.GetComponent <ItemNoisy> ();
            noisy.Init();
            break;

        case STATE.GARBAGE:
            garbage = this.gameObject.GetComponent <ItemGarbage> ();
            garbage.Init();
            break;

        default:
            Debug.Log("何かがおかしいよ! at Item Init()");
            break;
        }
    }