void Start()
 {
     if (gameObject.tag == "Player")
     {
         charaIcon = GameObject.Find("PlayerCharaIcon");
     }
     else if (gameObject.tag == "Enemy")
     {
         charaIcon = GameObject.Find("EnemyCharaIcon");
     }
     charaExpression = CharaExpression.normal;
 }
    public void changeExpression(CharaExpression expression)
    {
        charaExpression = expression;
        switch (charaExpression)
        {
        case CharaExpression.angry:
            charaIcon.GetComponent <SpriteRenderer>().sprite = angryFace;
            break;

        case CharaExpression.sick:
            charaIcon.GetComponent <SpriteRenderer>().sprite = sickFace;
            break;

        default:
            charaIcon.GetComponent <SpriteRenderer>().sprite = normalFace;
            break;
        }
    }