Etsuya Eizan attends Tōtsuki Culinary Academy, initially holding the 9th Seat of the Elite Ten Council before advancing to the 7th Seat during Azami Nakiri's tenure as headmaster. He operates a highly successful food consulting business, guaranteeing success for clients in the food industry. Having managed nearly 500 cases since middle school, Eizan commands exorbitant fees for his services, amassing significant wealth through connections with affluent culinary businesses. He sports a distinctive look: long, swept-back dirty blonde hair evoking a Japanese delinquent style, gold eyes, and rectangular glasses. Eizan frequently accessorizes with a rope chain necklace, multiple rings, and a Rolex-style watch. His typical attire features leopard-print shirts under unbuttoned collared jackets. While cooking, he wears a white chef jacket with teal accents, rolls up his sleeves, and removes his glasses. Eizan's personality blends shrewd business sense with ruthless pragmatism, measuring success solely by profit and privilege. He leverages his influence to manipulate outcomes, employing underhanded tactics such as bribing judges and rigging competitions like the 43rd Autumn Election to eliminate rivals. He nurses a deep grudge against Sōma Yukihira after Sōma's karaage stand success harmed Eizan's client, Mozuya Karaage, driving a vendetta where Eizan attempts to sabotage Sōma academically and orchestrates the planned demolition of Polar Star Dormitory. His culinary approach, termed "Alchemy," involves manipulating opponents' dishes through chemical components affecting taste receptors. Eizan specializes in exploiting sensory elements like fragrance, visual appeal, and sound to undermine competitors. Despite technical skill, he often relies on psychological warfare and external manipulation over pure cooking prowess. Eizan's background includes a delinquent past as a ruthless gang leader during his teens, shaping his leadership of a student faction that executes his schemes. He enrolled in Tōtsuki purely for profitability, rapidly generating unprecedented revenue for the academy. His rise within the Elite Ten was accelerated by supporting Azami Nakiri's coup, aligning with Central's authoritarian reforms to consolidate power. During the Régiment de Cuisine, Eizan battled Takumi Aldini in a beef-focused Shokugeki. He attempted to sabotage Takumi's dish using artichokes' cynarine to unfavorably amplify sweetness. Takumi countered by adjusting his recipe, securing Eizan's defeat. This loss, coupled with prior humiliation by Sōma, triggered a psychological breakdown. Eizan later recovered, rejoining the Elite Ten in his third year with a reformed perspective. He eventually reconciled with Sōma, shifting from animosity to mutual respect.