Mizuki is a quiet and reserved girl who is about to take the entrance exam. She lives with her rigid and possessive mother, concerned that her daughter's grades are not good enough to go to a good university. The only escape route for Mizuki is Mako, her only friend, with whom she shares confidences and can vent. One day, talking about the trip they plan to take after the entrance exams, Mako suggested to Mizuki an easy and quick way to earn money to make her dream come true. However, Mizuki couldn't suspect that her friend's seemingly innocent advice would have dire consequences for both of them...