Katsuya Serizawa, a 30-year-old esper, carries a history defined by social isolation stemming from his uncontrollable psychic abilities. Once a recluse paralyzed by anxiety and the fear of endangering others, his withdrawal broke when Touichirou Suzuki, Claw’s leader, recruited him. Suzuki’s capacity to withstand Serizawa’s powers offered stability, forging fierce loyalty that later wavered as Serizawa faced the organization’s ethical transgressions.
His evolving appearance mirrors internal transformation. Early depictions show him draped in loose hanten and jinbei, masking his form to mirror discomfort with confrontation. Unkempt, fluffy hair contrasts sharply with his post-Claw persona, where trimmed locks and polished attire reflect newfound self-assurance. Beneath his social awkwardness lies a gentle demeanor, evident in protective acts toward children—shielding Shou Suzuki during Claw’s downfall and supporting Tome Kurata in spin-off stories.
After abandoning Claw, Serizawa seeks redemption through Reigen Arataka’s agency, enrolling in night school to bridge educational gaps and pursue self-betterment. Guided by Reigen and Mob, he transitions from dependence on authority to autonomous action, exemplified during a yokai mission where strategic intellect merges with combat expertise sharpened in Claw’s elite ranks.
His dynamic with Shou Suzuki defies expectations. While Shou resents Serizawa’s past allegiance, Serizawa persistently prioritizes the youth’s safety, later extending an olive branch by inviting him to Reigen’s birthday celebration—an act underscoring his commitment to harmony over resentment.
Personal quirks include a fondness for gyudon, a distaste for spice, and leisurely browsing western fashion sites. The motto “If I can do it now, I will” anchors his pragmatic battle against anxiety, while skills like precise tea-pouring and knotting neckties align with his methodical nature. Post-series life balances psychic duties with ordinary ambitions, as Serizawa navigates friendships, studies, and gradual integration into societal rhythms.