Yuna and her husband both work as teachers at the same school, with her husband serving as advisor to delinquent students, Hinomori and Ichii. Just before summer break, he catches the two smoking and is forced to report them. As a result, they are stripped of their team jerseys and given a two-week suspension. After the suspension ends, during summer break, Yuna's husband becomes overwhelmed with club duties, leaving Yuna to take over their remedial lessons. Furious over their punishment, Hinomori and Ichii plot revenge against Yuna and her husband, setting the stage for their sinister scheme.