Ayuha Samaru is a high school student. She is honest and works hard at everything, no matter what. One day, she has trouble at a gyudon restaurant due to money. A man at the restaurant, Yoshitaka Hiromitsu, helps her out. The next day, she finds that Yoshitaka Hiromitsu has come to her school as a substitute teacher for her ill homeroom teacher. Ayuha Samaru now believes that Yoshitaka Hiromitsu is her fate in love. She keeps expressing her feelings to him.