Saishuu Shiken Kujira Progressive

Mutsumi, also known as Mucchan, and his friend Sae, Sacchan, reconnected several years after their initial meeting. They agreed to meet up again in a specific location, but Mucchan failed to show up. Later, while commuting to school, Mucchan encountered Sacchan, who had been waiting for him all that time. They briefly resumed their friendly activities together, but their reunion was short-lived.