In order to stop his classmates from bullying him, the protagonist, Kamiya Tooru, makes a false confession to a girl in his class, Hino Maori. Even though she knows that the confession is a lie, Maori says yes with the three rules: "Don't talk to me until after school," "Keep communication brief," and "Don't fall in love with each other". The two promise not to fall in love, but as they get to know each other, they find themselves drawn to each other. When Tooru finally couldn't hold back his feelings, Maori's words were unexpected. "I have an anterograde amnesia, and I forget things when I sleep at night. Everything that's happened in a day". Her memories and experiences were reset every day, and she wrotae down the day's events in a diary and woke up early in the morning to review them in order to keep her memory alive. Tooru is devoted to bringing her as much happiness as possible. However, such daily life did not last long. What is the "plan" that Tooru has devised to protect Maori's happiness? The raging climax and the fragile tenderness will wrap the world in warm tears once again.