Read manga: Futagami Double

manga
Summary:

Futagami Sousuke, 14 years old, is a normal student, wishing to live a normal life. But everything changes the day he sees a doppelganger of himself in his house.
Since then, the girl he has a crush on, Amane, will introduce him to another side of his world he had no idea about, and it won't be anymore the dear peaceful days for Futagami.