High school student Mariko (Ando Sakura) sings in the choir at theall-girls school she attends, and her biggest dream right now isto go to a music college. One day on her way home from school, sheaccidentally drops her bookbag into the sea. A man (Sasaki Takao)jumps into the water and recovers the bag for her, but all of herscore sheets have been ruined. From that day on, Mariko's newacquaintance becomes her bodyguard, walking her home everyday. Butfor some reason, he refuses to tell her his name.