Sosaku Yubiwa, a first-year middle school student at Yubiwa Academy, carries the title “Sosaku the Artiste” as a core member of the Pretty Boy Detective Club. Heir to the Yubiwa Foundation—the entity governing the academy—he wields de facto presidential authority over its financial and administrative operations, leveraging his reputation as a prodigy excelling in both business strategy and artistic pursuits.

Inherently reserved, he communicates through nuanced gestures and expressions decipherable only by the club’s leader, Manabu Sotoin. His soft-spoken demeanor often misleads outsiders like Mayumi Dojima into mistaking his silence for aloofness. Yet he adapts fluidly to social demands, exemplified during a casino infiltration where he shed his reticence to engage openly.

A polymath artist, he crafts paintings, sculptures, and flawless replicas pivotal to the club’s cases, from forging decoy artifacts to spotting counterfeit bills. His discerning eye detects minutest flaws in others’ work, a skill sharpened by his own mastery.

Clad in a lab coat draping over his uniform with sleeves obscuring his hands, striped trousers, and black boots, his aesthetic shifts in the manga adaptation to a beige cardigan and plaid pants, though his enigmatic air persists. Beyond artistry, he bankrolls the club’s endeavors, merging fiscal stewardship with investigative support.

Spin-offs like *Mazemonogatari* expand his lore, depicting collaborations with Manabu at North White Snake Shrine for stargazing ventures. His narrative arc consistently underscores his duality: a detached savant balancing corporate obligations with unwavering loyalty to the club’s missions.