Orange: Omnibus Vol. 1 Manga

A plea from the future.

On the day that Naho begins 11th grade, she receives a letter from herself ten years in the future.  At first, she writes it off as a prank, but as the letter's predictions come true one by one Naho realizes that the letter might be the real deal.  Her future self tells Naho that a new transfer student, a boy named Kakeru, will soon join her class.  The letter begs Naho to watch over him, saying that only Naho can save Kakeru from a terrible future.  Who is this mystery boy, and can Naho save him from his destiny?  The heart-wrenching sci-fi romance that has over one million copies in print in Japan!