Forget Me Not.

Takashi Hayama is a third year high school student. He falls in love with Azusa Oribe at first sight and they begin to date. One day, Azusa tells Takashi "people who meet me, forget about me several hours later." Takashi doesn't believe Azusa, but by chance he realizes that he forgot about Azusa. So he won't forget Azusa, Takashi begins to leave a note for himself and Azusa.