After Mina Yukimura's (Mimi) Father die in a car wreck leaving her, her younger brother Rui, and their mother with a large amount of debt. She must now take care of her brother and come up with a way to make money while keeping up her grades at Iron Cross Academy. To pay off the debt she works as a tutor for Yuut Sugiyama. Yuut is best friends with her younger brother and comes from a rich family. As a nerd, she gets all A's. She worries about her brother who's been acting out of lately and her mother who's been working two jobs without rest.