Tamotsu Fukuda, born September 12, 1985, in Japan, possesses a striking physical presence at 190 cm (6'2"), with chartreuse eyes and long, spiked blue hair swept sharply to the left. His everyday attire—a crisp white shirt, black trousers, and suspenders—is accentuated by silver piercings: three adorning his left ear, two beneath his lower lip, and two above his left eyebrow. A green hooded coat often shrouds his frame in public. Post-capture, he dons the Kura prisoner uniform: white trousers, a matching shirt, slippers, and a distinctive bracelet on his right wrist. Dominating his appearance is a jagged scar spanning the right side of his skull, a permanent reminder of his self-administered drill procedure.

Fukuda’s history remains largely enigmatic, though his struggle with arithmomania—a compulsive fixation on numerical patterns—drove him to extreme measures. Desperate to cure his condition, he drilled into his skull, eradicating his compulsions but leaving the scar. This act birthed a delusion that such methods could liberate others, propelling him to murder victims via cranial perforations under the epithet "The Perforator."

Following arrest, Kura repurposed his intellect, recruiting him as a Mizuhanome pilot under the alias Brilliant Detective Anaido. Within virtual id wells, he infiltrated killers’ psyches to unmask their identities, leveraging his sharp memory for numerical precision. Despite his crimes, Fukuda exuded calm wit and charm, forming an unlikely alliance with investigator Koharu Hondomachi. Their partnership proved pivotal in exposing John Walker, with Fukuda’s insights cracking the case. Their bond deepened into mutual respect, culminating in his fatal intervention to shield Hondomachi from Nahoshi Inami—a sacrifice that plunged him into a coma.

Fukuda’s psyche intertwines trauma, intelligence, and contradiction. His actions, shaped by a fractured past and self-made cure, reflect a mind as calculating as it is unorthodox, forever balancing destruction and redemption.