From Blissful Sin:

After failing his midterm exams, Minami's mother recruits a tutor to help him with his studies. Luckily for Minami, the tutor turns out to be Uta, his childhood friend has hasn’t seen for years. Minami’s excited to spend time with his friend, but Uta seems to be excited for an entirely different reason…

Renta!
Juné (Print & Digital)
Juné Manga edition is uncensored.

Uta, a seemingly perfect guy with no weaknesses, is invited to Minami's home as a private tutor. Minami's skills in bed are as pathetic as his grades, but thanks to Uta's help, he starts scoring better and "scoring" better! Excitement gives way to an all-out rollercoaster ride as they begin their lessons in love!! Also included in this volume: A sweet, two-part romance about a hair stylist saving for marriage who ends up living with a divorcee, and a short story about a rough-and-tumble rival pair who can't stop arguing over who should "top" long enough to admit their feelings!!