The main character, Makoto Kougami, has just transferred to a new school. He has a crush on his beautiful math teacher, Shiori Toono. She is a serious and inflexible girl who is not well received by the male students. However, Makoto is crazy about her. One day, he sees her taking care of a cat. The two quickly become closer through their common topic of conversation about the cat she keeps at home. Can Makoto be able to break down her firm guard?