Too-shy Yaya is no match for the clever manipulations of the latest transfer student, Megumi Hino-Hino-chan-whose bright, optimistic exterior shields a perfect storm of selfishness, jealousy, and sadism. Hino-chan has her tentacles in all aspects of Yaya's life, including her budding relationship with nice-guy Moriyama and a strange unspoken animosity with rakish, ex-rock star Shohei. Perhaps Yaya's aggressive alter ego Nana can cut Hino-chan down to size ...especially when Yaya is pressured into signing a legally binding contract with her arch enemy!