Potamos infiltrates Saint Hanazono Middle School by transforming herself into a human. As the transfer student Kawanami Hiromi, she wastes no time endearing herself to the boys, but is strangely attracted to Yousuke in particular. When Hiromi declares herself the manager of the soccer team, Momoko is forced to sit on the sidelines and watch the new girl put the moves on Yousuke. To make matters worse, Potamos has called upon the devil Shimoshimo to freeze happy couples in chunks of ice.