Katsuya Serizawa is a powerful Esper who was formerly a part of the Ultimate 5 and member of Claw. He now works at Spirits and Such Consultation Office. Serizawa was a very sheltered and naive person prior to leaving Claw. He placed all his trust in Toichiro Suzuki and looked up to him as a personal savior, and followed his orders without question. Before beginning his work at the Spirits and Such Consultation Office, if he was separated from his umbrella he would panic and completely lose control of his psychic power, which would cause heavy damage to his surroundings. He was haunted by a deep fear of his own power.