Maya Takagi, a sister who lost her parents in an accident and became financially distressed, dropped out of college to support her brother and became a prostitute even though she had no sexual experience.

Her brother, Masumi Takagi, had no idea about his sister, was listening to the store manager's usual story about a prostitute during his break and was shown photos of the girl on the panel, who the manager said had a similar background and would be a good match. When he looked at the panel, there was a girl with a striking resemblance to his sister and a stage name that was Masumi's nickname, "Jun".

Masumi believed his earnest and gentle sister would never do something like this. Suspecting a mistake, he began to investigate.