Koto-chan is a member of the brass band club and is enjoying her youth. Her dream is to play in the alps stand at Koshien. She seems like the picture of a serious girl. But in reality, she is anything but. Recently, it seems that "daddy-stepdaughter" activities have become popular at her college, and she is too busy with club activities to have a part-time job. She wants to buy some things, and she also wants some spending time. And actually, she also has a curiosity to experience a proper sex. .... So today, miraculously, we got to know our lovely girlfriend! She masturbates while still wearing her uniform, without even taking off her pants. When she saw how embarrassed we were, we noticed that her pants were covered with naughty stains. And then they have sex while wearing their uniforms!