Aoi reunites with her sexually harassing teacher from her school days at a hot spring. She has a dark past in which the teacher found out her weakness and sexually harassed her. Not wanting her secret to be revealed, the teacher calls Aoi to the men's bath in the middle of the night and plays with her big breasts. Even though she resists, no one comes to help, and he forces her to cum inside her! The tragedy doesn't end there, as other customers appear and continue to gang-rape her, cumming inside her. Raped by the teacher, then raped by regular customers... the despair repeats. What should have been a fun trip suddenly changes into a rape hot spring.