Her husband is away on a business trip, leaving her father-in-law at home. Naturally, she is not satisfied and fills her loneliness with masturbation. One day, her father-in-law witnesses her in such a state. Feeling sorry for her, he forces himself on her, saying he will satisfy her. Although Aimu resists at first, her guilt towards her husband gradually disappears, and she begins to seek her father-in-law for the pleasure she cannot get from her husband.