Yankee-kun wa Otosaretai

Meet Mikita, a mousy otaku who is constantly getting bullied at school by the object of his affections: a delinquent named Komazawa. Unfortunately for Mikita, the trouble doesn't end there: one day, while rushing to class, he bumps into Komazawa, who, in the hustle and bustle of things, accidentally takes his notebook home. After peeking inside, Komazawa realizes that the notebook is full of hardcore smut...featuring a guy who looks an awful like him! Even though he's grossed out, he can't help but be turned on by it. When a hysterical Mikita shows up looking for the notebook, will Komazawa force him to admit to his fantasies...?

(Source: Kaiohsha, translated)