Aitsu to Ore.

Takeru's mother is right about to remarry. That is a great opportunity for Takeru to live with a real family and most of all to have a big brother, Shin. Things do not actually turn out the way he expected though.

A little while before Christmas and waiting for his girlfriend, Takeru hears a couple of people discussing about money for sexual favors. Kind of curious, he turns around to check out the chick, but it happens that both parties are male, and the oddest comes when Takeru realizes that the one prostituting himself is Shin, his new stepbrother…

(Source: MU)

Included one-shots:
Volume 1: Shounen S
Volume 2: Itsuka Hana Ippai no Niwa de