Orange by Ichigo Takano

On the first day of 11th grade, Naho receives a letter from her future self directing her to save the life of a Kakeru, new student at her school.  To her surprise, there is a new student that day who becomes a good friend.  Now, with the help of the letter and her friends she must somehow save Kakeru.

This was an unusual manga that was realistic with hints of the supernatural.  It deals with the very serious subjects of self-confidence, depression and suicide.  With only two volumes in the series, it is a quick read for those who like manga.