18+ Love Hotel Ikou yo♡

It's been three months since they began to date. They have yet to take their relationship beyond holding hands. Now, for the first time in his life, Tatsuya walks the path towards a hotel with his girlfriend, Kaori, expecting to graduate from virginity. What he doesn't know is that Kaori has a secret... A love-comedy story centered around what the Japanese call "love" hotels and this cute couple whose secrets will be revealed as they deepen their relationship!

(Source: MangaHelpers)

Included one-shot:
Volume 1: Aijou Hyougen II