Gō Reietsu acts as second-in-command of the Kimengumi. His family operates a sake store, and he resides with his uncle's household. Despite being underage, he occasionally consumes alcohol and becomes intoxicated. Academically, he faced significant challenges, requiring three attempts to pass the high school entrance exam.

Gō stands as the Kimengumi's strongest member, fitting the "Dumb Muscle" archetype due to his limited intellect aligning with the group's poor academic performance. His appearance features notably large, prominent eyes, which earned him the nickname "Manako no Gō" (Eyeballs Gō). He possesses a volatile temper, often reacting with aggression or fighting when provoked. While frequently displaying jerkish tendencies—including manipulative behavior and underhanded tactics to win, cementing his role as the group's "Token Evil Teammate"—he simultaneously shows genuine loyalty and care toward fellow Kimengumi members, making him a Jerk with a Heart of Gold.

He channels his aggression into a passion for professional wrestling. Gō occasionally exhibits reality-warping abilities alongside other Kimengumi members, performing improbable feats like walking on water, typically for comedic effect. His dynamic with Chie Uru, Yui's best friend, is marked by their similar hot-headed personalities, leading to frequent clashes and mutual annoyance. This relationship also carries Ship Tease, implying romantic tension or attraction, particularly from Gō's perspective. He fiercely protects all Kimengumi members, refusing to tolerate mockery of his friends.

Throughout all official media—including the original manga, anime series, movie, and sequel manga Flash! Funny-face Club—Gō's background, personality, and role remain consistent. He serves as the temperamental but loyal enforcer during the Kimengumi's misadventures.