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 has come to her school as a substitute teacher for her ill homeroom teacher.
Ayuha now believes that Yoshitaka is her fate in love. She keeps expressing her feelings to him.