Seishun Forget!

Natsuki Taiyou believes in living sincerely. On the first day of high school, he meets a girl on the way to school, instantly falls for her, and proposes. She agrees but flees before revealing her identity. The next day, he discovers she is his classmate and feels a sense of fate connecting them. However, the following day, she no longer recognizes him, leaving him puzzled about the reason behind her sudden forgetfulness.