Ch.1-2.4.5: One day, S call boy Hiro accepts a strange client, K-san. Growing up, K-san's religious mother banned anything sexual, so K-san wants Hiro to make him use to sex. However, K-san turns out to be Kuki, Hiro's boss at his intern job
Ch.3-4: Kazushi becomes interested in his serious seminar senpai Tsukasa and begins regularly visiting him with the excuse of returning a pen. When Kazushi realizes Tsukasa has feelings for his brother-in-law, he also realizes his own feelings
Yoru no Rakka