From Chibi Manga:

We are secretly doing something that we shouldn’t be doing. The secret love and sex between students are drawn in the Omunibus! The secret love that we shouldn’t be doing. The classmates’ secrets and sex are drawn in 4 stories.

Story 1
The person that I like has a girlfriend. But, since I want to be more than friends, and want him to touch me like I was his girlfriend…so I invited him into the bed with me!?

Story 2
I witnessed the female honor student who lives next door to me having an affair!! While he has become worried about her, his heart becomes disturbed by her unexpected honesty.

Story 3
I don’t like a guy who only wants to have sex all of the time! The honor student cried saying she didn’t want to be hurt…but the truth is he’s a very sadist guy!! She is constantly being put down and always pulled in different directions but!?

Story 4
I have zero sex appeal and I am constantly being called “short monkey” by that guy and he suddenly kisses me! She felt the defeat…!?