Kizaki, who was in charge of the article about Yumeji and Kazue's discussion with the master of flower arrangement, deceives Yuriko and takes her virginity. Yumeji, who loves her sister, goes to protest, but Kizaki has already conspired with Kazue, who plans to take over the Shimabara school. imprisoned sisters. The noble Yumeji decides to accept the blame without giving in. And the days of sister confinement training begin...