Katsuko Kurose is a stubborn female teacher who takes her students seriously in accordance with her beliefs. A workaholic woman who has entered her thirties as a virgin, the first man she ever loved was her own student, Jun...... 
 
Katsuko is a beginner in love, but her strong and demanding personality gets in the way, and she sometimes unleashes unexpected words on Jun. Even so, she and Jun grow closer, little by little, and Katsuko and Jun's "secret love" slowly deepens. 
 
Then comes Jun's birthday. In Katsuko's room, one of the few places where they can meet in secret, the two are united for the first time. They were able to dedicate their first time to their beloved...... That was the only thing that mattered to both of them, and they could feel their bond deepening. 
 
One day, however, Jun's classmate Shinohara sees them meeting secretly at the school. That night, Shinohara visited Katsuko's room and threatened her with a story about this, and then he started to fuck out every inch of her body......!!

Unsweet: Netorare Ochita Onna-tachi - Jokyoushi Kurose Katsuko-hen