Formerly, Ryouma Tokugawa was known as a strong and intelligent member of Division 0 in the Paranormal Investigator International, even holding a position akin to a vice-chair under the leadership of Albert Hoisenberg. However, after accidentally killing civilians to protect his sister, who had become a monster, he was then imprisoned for 30 years, and his sister was subsequently destroyed. Thirty years have passed, and Ryouma has just been released from his imprisonment, standing outside the prison building, looking around. "Nothing has changed, huh?"