Kowamote Onii-san to Ubu Gyaru-kun

In order to change himself from being shy and friendless, Hatsutou makes his debut at university as a gal boy. One day, drunk, he approaches a virgin on the street and asks if he'll suck him off, but for some reason, a scary-looking guy says, "That would be nice," and takes him to a hotel. Even though it's his first time doing anything naughty, the guy ends up making him melt with pleasure!!?

(Source: Kaiohsha, translated)

Note: Includes one extra chapter.