Since his wife passed away, Yuriko, her father-in-law, has been lazing around with no motivation, so she comes to look after him. Her husband, Keigo, has been cold towards Yuriko recently, so she has been trying to ease her loneliness by meeting with her father-in-law. However, seeing her father-in-law's kindness and devotion to his late wife, Yuriko begins to fall in love with him. Then, one day when her husband is away on a business trip and she is left alone with her father-in-law, Yuriko takes a bold and lascivious action with her burning passion in her heart...