Calling (OOTSUKI Miu)

From Iridescent:

Hinamura Kazuaki, working in general affairs at an IT firm believes his
life is way too ordinary until he meets Aratani Kira. Kira's life is the complete
opposite of Kazuaki's. He's a porn actor.
Kazuaki is not keen on getting involved with Kira, but he finally gives in to Kira's
persistant yet sweet nature. As they continue to meet on a regular basis, Kazuaki
realizes that his life may be changing into one with a lot more excitement than he can
handle...