Due to the main Girl's mother poor health accepts teacher's monetary help who ends up raping and blackmailing her. She isn't falling for him btw, she just has no choice to find another way to help her mother's hospital fees.
The girl came from a poor mother-and-child family and was unable to earn living expenses while her mother was hospitalized due to illness, so she had no choice but to accept the teacher's request for prostitution. It's an ending that seems like there will be a sequel.
>I have been close to my childhood friend Mitsuki since we were little. We played together and went to and from school together. I thought this kind of everyday life would go on as a matter of course... >However, the day Mizuki's mother collapsed The normal routine begins to go askew... Mizuki is attacked by a teacher who takes advantage of her position and lusts after her. >The teacher escalates more and more. >Despite the feeling of being threatened and having no choice, Her body is gradually drowned in an irresistible pleasure...