Oniichan kara Nigerarenai!: Doutei Hishojo ni Narimashita

Kohaku, a college student who celebrated his 20th birthday while still a virgin, suddenly lost his part-time job and a place to live in one day...!! He was in trouble and didn't know what to do, but then, his brother-in-law, Ten, showed up and let him live with him from now on! Kohaku fell asleep on his luxurious, fluffy bed... but when he woke up, for some reason, Ten was putting his hot and big dick in his butt!? "You don't need to jerk off by yourself. I'm here for you," he said. What's that supposed to mean!?

(Source: Mobile Media Research)