Reigen Arataka runs the Spirits and Such Consultation Office as the self-proclaimed "Greatest Psychic of the 21st Century," despite lacking authentic supernatural abilities. He appears tall with reddish-blond hair, dark brown eyes, and expressive features, usually clad in a grey business suit and tie. His attire adapts to situations, including unconventional disguises like a high school girls' uniform during investigations.

He fabricates psychic techniques—Salt Splash (throwing salt), Salt Heap Punch (salt-coated punches), and Cheese-Burger Tornado (a spinning fist strike)—while offering practical services like massages marketed as "spiritual cleansings" and digital photo edits for "spirit removal." These deceptions sustain his consultancy, though he ensures client satisfaction through refunds for unresolved cases and legitimate acupuncture-based massages alleviating physical discomfort. His approach blends showmanship with insightful counseling, resolving clients' emotional or spiritual anxieties through dialogue and pragmatic solutions.

Initially exploiting Mob's psychic powers for profit, Reigen transforms into a protective mentor. He instills ethical principles in Mob, emphasizing that harming others is wrong, and supports his personal growth, such as athletic training. Despite relying on Mob's abilities, Reigen risks his life defending him against armed adversaries without powers. Their bond fractures when Mob temporarily leaves due to Reigen's overreliance, forcing Reigen to confront his fear of abandonment and acknowledge Mob's independence. Their reconciliation strengthens their relationship, with Reigen affirming Mob's worth beyond psychic talents.

During Mob's absences for academic commitments, Reigen handles cases alone or with assistants like supernatural enthusiast Tome Kurata. He initially resists Tome's involvement due to her lack of powers but eventually accepts her aid. On investigations, he shields her from dangerous spirits despite his fraudulent persona. His social intelligence enables him to counsel adversaries, including Claw members, toward self-improvement while rejecting esper supremacy. He notably exposes the spirit Mogami's deception by spotting speech-pattern inconsistencies when trained espers were deceived.

Reigen's background includes above-average academics and an unremarkful salaryman career before founding Spirits and Such. His motivation—"to make a difference"—surfaces via a leaked school essay during a public fraud scandal. The scandal's fallout reveals his primary fear: losing Mob's respect. When Mob affirms Reigen's inherent kindness despite deception, it validates Reigen's underlying integrity. His arc concludes by rejecting temporary godlike psychic powers, dismissing them as irrelevant to genuine human connection.