Even though it wasn't supposed to be like this (Konna Hazu ja Nakatta no ni)

1-5. Though Unexpected

Ryuzaki is an aloof high-school student who likes to seclude himself in the infirmary. This, however, teases the stubborn school doctor, Wataru, to seek out other men to quench his lust—!? Or is this love? They both wonder as they desperately fight with their morals. To do or not to do?

-Fantasyshrine

One Summer, Two Men

Kitaoka is a successful man at his prime, he is the president of a booming company, admired by men and desired by women, he have the look and the charisma but he's bored and seeking for something new... On a whim, he had a one night stand with a strange boy who came from nowhere and was willing to sell him his body, but is it just a fling or there is more behind it?