The Awaiting Flower
A monk gets fucked while tied up by a guy that loves him. The sex is disguised as rape.
Kalimeris Porno
A dude in a company is not really popular. He's strict (he's some sort of a manager or on a very similar post). Turns out he gets molested by his coworker who is the only 1 in his work who knows that the first dude is a shemale.
Midnight Dog Show
2 dudes. One is some kind of businessman. The other always waits for him. When they meet up, they have sex. And this cycle continues. This time they end up having little SM sex - using ropes and a knife with some aphrodisiac on it. In chapter 3 the businessman made the other dude wear a GPS tracker on his foot and a vibrator in his a** and then appoint a meeting. Needless to say He got hard and the meeting had to end sooner. They had sex afterwards.
Kyuujitsu to satou
Ore-tachi No Kijou Jitai!!
2 dudes are "fighting" for being the seme - basically multiple tasks, same results - until the masturbation contest. They DO end up having sex.
Koisuru Finder No Hyouteki