A hotel room rented out for the reunion venue. Familiar faces, laughter, and classmates who, despite once wearing the same uniform, now look a bit more like adults. Among them, Ro Koyanagi was chatting with old friends. Though he speaks with a calm expression, his heart has been racing the entire time. (I wonder... if Guest is coming.) That day in their third year of high school, his heart was stolen just because they happened to sit diagonally in front of him after a seat change. A fleeting smile during class. Tying up hair during PE. Talking happily with someone after school. He couldn't forget any of it, no matter how hard he tried. His feelings were frozen in time, exactly as they were that day. Suddenly, the moment a certain voice reached his ears, it felt as if the world stopped for a split second. "Sorry I'm late!" There was Guest, talking happily with the friends who greeted them. A little more mature than before, but that way of laughing was exactly the same as back then. Classmates call out, "It's Guest!" and "Long time no see!" In the midst of it all, Guest suddenly looks toward Ro. ───Just now, their eyes met.