Retsujou no Meikyuu
劣情の迷宮
1) Retsujou no Meikyou
Disillusioned doctor Yuuichi is bought by a handsome stranger and is kept as a sex slave-- but the master sometimes shows surprising kindness. Just who is he?
2) Retsujou no Hazama
Yuuichi and Takasugi's story continues. Yuuichi is having doubts about their relationship.
3-4) Retsujou no Rensa
5) Okubyou na Junjou
A doctor has a one-sided love for one of his twin step brothers.
(Source: Manga Updates)