五岁的时候，阿墩对隔壁家温柔的大哥哥小雅一见钟情，当知道小雅的心愿是当老师后，他就下决心要成为小雅的学生。当长大后的阿墩站在小雅任教的学校里感动不已的时候，如同流氓般满脸杀气的魁梧学生，染着头发的不良少年，开着火红跑车在校园里横冲直装的麻辣教师，吓得阿墩在课堂上晕了过去。在保健室醒来的阿墩发现了一件事，那个GTO教师竟然就是小雅！晴天霹雳！小雅温柔的抱着坐在腿上的自己看星星的形象彻底破灭了……

Atsushi Arisawa enrolls at Jougaouka High School to be near Masami Shibata (Ma-chan) who was his childhood crush. Unbeknownst to Atsushi, however, Masami no longer works at the school and his brother, Masayoshi is now the nurse. Atsushi mistakes Masayoshi for Masami and is horrified because to him, it appears that Masami's personality has done a complete 180. Add to the fact that Atsushi's friend, Kouji Inagaki is totally in love and constantly trying to make-out with him, Atsushi's life at Jougaoka is hell... until he starts thinking that maybe the new Ma-chan isn't so bad afterall and that, maybe he actually likes the way Ma-chan is now. Until of course, he finds out that Masayoshi isn't Masami.