Drunken Chemist's manga / #childhood friends(16)

Kowarekake No Omocha

Complete | Cj Michalski | 2005 released

Koushaku no Himeta Kuchizuke

Complete | FUJIKAWA Ruri | 2008 released

Kedamono Kareshi (aomoto Sari)

Complete | aomoto sari | 2013 released

Wanko to Nyanko

Ongoing | AMASAKI Yoshimi | 2000 released

Kishidou Club Bangaihen

Complete | NISHIMURA Shuuko | 2000 released

Komatta Yatsu

Ongoing | yoshihara yuuka | 2000 released

Saihate no Kimi e

Complete | MINAMI Haruka | 2000 released

Hmmm this manga has a similar plot with kowarekake no omocha where uke-san came from a poor family (in this case, his parents were deceased) and was bought by a rich family household to be their son's playmate/companion and when they're both grown up seme-kun treats uke-san as his sex-slave, although I think seme-kun (akihito) is not as forceful as Kengo-san. Both of them never show that they're interested in girls, moreover seme-kun often jealous when uke-san befriended with other guy.