The introverted Aoyagi Rikka (voiced by Junko Minagawa) always has inexplicable scars on his body, and he naturally becomes the target of bullying by his classmates. But such Rikka still has a gentle side. He holds a camera, hoping to create common memories. Rikka was not like this before. It all started with the murder of his brother Aoyagi Kiyoaki (voiced by Ken Narita). Kiyoaki's death brought a devastating blow to Rikka's family and became a lingering shadow for Rikka. Suddenly one day, a blond man named Agatsuma Kusato (voiced by Katsuyuki Konishi) appeared in front of him. Kusato told Rikka that he was Kiyoaki's fighter, and each fighter had a master who could control them with words, and his former master was Kiyoaki. Now that Kiyoaki is dead, he is entrusted by Kiyoaki to become Rikka's fighter. Kusato also told Rikka that he found something strange about Kiyoaki's death. Rikka, who loves her brother, secretly decided to work with Kusato to find out the real cause of her brother's death.