Hoge

Model.cs

using UnityEngine;
using System;
using System.Collections;

public class Model
{
  public Action<string> OnChange;
  protected void Changed(string propertyName)
  {
    if(OnChange != null) OnChange(propertyName);
  }
}

RPGStatusModel.cs

using UnityEngine;

public class RPGStatusModel : Model
{
  public RPGStatusModel(string name, int hp, int mp, int attack)
  {
    this.Name = name;
    this.HP = hp;
    this.MP = mp;
    this.Attack = attack;
  }

  private string name;
  public string Name
  {
    get { return name; }
    set { name = value; Changed("Name"); }
  }

  private int hp;
  public int HP
  {
    get { return hp; }
    set { hp = Mathf.Max(0, value); Changed("HP"); }
  }

  private int mp;
  public int MP
  {
    get { return mp; }
    set { mp = Mathf.Max(0, value); Changed("MP"); }
  }

  public int attack;
  public int Attack
  {
    get { return attack; }
    set { attack = value; Changed("Attack"); }
  }

  public void Damage()
  {
    HP--;
    Debug.Log(string.Format("Damage HP:{0}", HP));
  }
}