Katakura Kippei is every bit a high‑school playboy, spending his days flirting with any girl he sees while responsibility is always the last thing on his mind. One day, however, he returns home to find that he must take full‑time care of his five‑year‑old cousin, Yuzuyu. Kippei’s aunt, Miyako, has disappeared, leaving Yuzuyu seemingly abandoned. With Kippei’s lack of responsibility and limited childcare experience, coupled with Yuzuyu’s wounded heart after her mother’s disappearance, the two of them face a bumpy journey together. Based on the manga by Maki Youko.