Piperka

Mashiko Yamatashi was a girl with amnesia. In the beginning of her first year in high school, Mashiko met up with her "old friend," Takashi Atori, who had been oversea for a year. However, there seems to be more to it than just friendship between those two. Regarding Mashiko's memory lost, no one wanted her to remember her past. What could be so bad about "the past" that no one wanted to tell her about it?