Bomb Heaven
Ongoing | kano shiuko | 2012 released
Ai no Kotoba mo Shiranaide
Complete | honjoh rie | 2008 released
nice story. Only thing is that these three blonde guys look pretty similar sometime. Glad the story doesn't put all three of them in one setting.
Otouto ni Koi Shitara
Complete | SAKURA Ryou | 2000 released
the first step-brother story is my fav one.
Osananajimi Kussetsuritsu
Ongoing | MINAMI Haruka | 2000 released
http://www.ikanman.com/comic/8791/
Toshishita no Ryuugi