Step x Step!!

Teppei, a 16 years old who had once tried to elope with his first love who at that time was a cute little boy. But, when they meet again, has turned into a perverted harrassing king! Adding onto that, they are now 'brothers' after their parents' remarriage, living under one roof... What is install fo Teppei's love and innocence?
(Source: MangaFox)