Part 1 of the Kuudere JK (Cool-Dere HS girl) series.

Kanata Tanaka, an introvert, and his classmate Mio Yamamoto, a cool and mature-looking girl, have been assigned to inspect the gym storage room.

Mio, who finds herself alone together with him in that room, has her guard up about getting assaulted; but out of nervousness she accidentally knocks something over, a clumsy mistake that she would never usually make. Kanata is unable to suppress his excitement at the sight of her being clumsy, which he finds to be cute.

In the middle of all that, a teacher locks the gym storage room by mistake. The two of them wait for a while, but help doesn't come. Kanata, who thinks Mio was actually thinking something erotic might happen, summons his courage and begins to massage her shoulders. Moreover, under the pretext of tickling her, he keeps touching her body over and over while she's dying of laughter. Between "playing around" and "being serious", he makes a mess out of Mio. While nearly fainting from all this she continues to guard her private parts, but she's got no way to resist a boy's strength and gives in.

This introvert who's lost control won't stop, and just like that, bareback sex! Raw creampies! While they're doing things like having sex in the missionary position and forceful doggy style sex, right outside the gym storage room there's a random love confession scene happening...!?

(Source: DMM)