The Shiina couple work as teachers at the same school. The husband is troubled by two delinquent students, Himori and Ichii, in the club he is the advisor for. Just before summer vacation, he discovers them smoking. He is forced to report them, and they are stripped of their uniform numbers and suspended for two weeks. After their suspension is over during the summer vacation, the husband is busy with club activities, so Yuna ends up teaching the two students extra lessons. The harsh punishment they receive leads the couple to direct their anger towards Yuna, and they plot revenge against the couple...
