An affluent medical professor, Komiya, and his bossy wife, Tokio, are to look after Setsuko, their high-spirited niece from Osaka. Setsuko is a liberated woman who does what she wants, including smoking, even though she is a minor. On Saturday, the professor does not feel like going to his weekend golf game, but his wife packs him off anyway. So he leaves his bag at the apartment of his student Okada, and goes to a bar with a friend. Setsuko traces him there, and insists that he take her to a geisha house. When she gets rather tipsy, the professor calls Okada to take her home, while he sleeps at Okada's. The wife becomes suspicious of Setsuko when she sees Okada bringing her home, and also of her husband when she discovers that he did not go golfing.
另一方面，男主人公是一家玩具公司的富二代，过着极其奢侈和浪费的生活。由于开支过多，他激怒了父亲，被调到了财务部门。价值观完全相反的两人莫名其妙地开始同居，并逐渐点燃了爱情的火花。
