If I Become Friends with Benefits with My Bad Friend, I Might Just Fall for Him

An is a young office worker who appears to be a glamorous, confident woman at work, but in reality, she has never been able to truly enjoy sex and keeps breaking up with her boyfriends because of it.

One night, her longtime friend and secret crush, Kei Hoshikawa, reveals that women have dumped him because of his unusually large size. Taking the conversation as a joke, the two of them end up crossing a line they never expected to.

What begins as an impulsive arrangement between longtime friends gradually becomes something much more complicated, as An starts experiencing feelings and pleasure she never knew she could have with him.