Ecchi transformation life starting from cosplay.

The main character is Chiyuri Naruse, an otaku high school girl who loves anime and manga. In high school, she was eager to become her friend with an otaku "friend" like herself, but she was having a hard time finding her. One day, she hears a rumor that people who seem to be "friends" are gathering in the old school building, which is off-limits. When she looked into the classroom where she heard voices, she saw people in cosplay doing obscene things. And when Chiyuri is asked if she would like to try cosplaying as a certain eroge character...
A youth romantic comedy of a thrilling Narikiri girl!!