Tadashi Kikuchi, codenamed Snake in underground skateboarding circles, operates as the steadfast secretary to a powerful political figure. Raised within a lineage of servants to the Shindo family, his lifelong service began in childhood. During Ainosuke Shindo’s turbulent youth, Tadashi introduced him to skateboarding as an emotional refuge—an act that unknowingly ignited Ainosuke’s fervent passion, later clashing with familial expectations. Standing at 182 cm with a lean frame, Tadashi’s sharp features include purplish-black hair, piercing green eyes, and a distinctive mole beneath his right eye. He adheres to a polished professional wardrobe of black suits and lavender ties, contrasting with his covert "S" identity: a green bomber jacket, red cap, and black sweatpants. Subtle design cues, like muted colors and minimal eye highlights, mirror his restrained demeanor and role as a shadow orchestrator. Formal and emotionally guarded, Tadashi embodies loyalty, concealing inner turmoil beneath disciplined composure. Mocked as a subservient “dog,” he harbors profound concern for Ainosuke, compelling him to enter the "S" tournament as Snake. His goal: defeat Ainosuke to sever his ties to skateboarding, which he now deems destructive. His skating echoes fluid, rhythmic grace, shaping Ainosuke’s technique without its aggressive edge. Guilt shadows Tadashi’s past—introducing skateboarding led to Ainosuke’s skateboard being destroyed by his father. This remorse fuels his resolve to erase the sport from Ainosuke’s life. As "S’s" unseen manager, he masterminds events, directs staff, and monitors surveillance, proving both meticulous and adaptable. Symbolism weaves through his persona: serpentine motifs on his skateboard, an alias evoking biblical temptation, and a name bearing the kanji for “loyalty.” Fleeting cracks in his reserve—like voicing unease over Ainosuke’s choices—hint at buried emotions. Expanded media, like the OVA *Extra Part* and manga *SK∞: Chill Out!*, elevate him from supporter to protagonist, unraveling his covert influence and past. Across narratives, his struggle between duty and autonomy intertwines with his fraught bond to Ainosuke, framing a legacy of silent sacrifice and quiet consequence.