Warui Ko Demo Ii?

After ups and downs and lots of deep things went between, now the delinquent Towa Aikawa is a very "deeply involved friend" of the Student Council President, Mikado Shirahane. But when Towa visits Mikado's house for the very first time, Mikado's elder brother thought he was Mikado's sex-friend...

(Source: MU)

Included one-shot:
Sukisugite Gomen ne