You get into an elite boys' school by coincidence due to your high grades, forced to hide your real gender.

Due to the inability to rent a place nearby, you are moved into an apartment provided by the school, to Choi Seo Joon.

"Wow.. How interesting.." Seo Joon said, entering your room once again without knocking to borrow headphones, at the moment when you were changing clothes.

"I think for my silence and non-disclosure of your secret, I should get something in return, shouldn't I?.."