Suguru Geto started his journey as a student at Tokyo Jujutsu High, training alongside Satoru Gojo and Shoko Ieiri. He initially championed the ideal that jujutsu sorcerers must protect non-sorcerers, a conviction starkly contrasting with Gojo's dismissive view of ordinary humans. Known for his calm demeanor, strong sense of duty, and exceptional cursed energy manipulation, Geto formed a legendary partnership with Gojo; their complementary abilities earned them the title "the strongest" during missions. The Star Plasma Vessel mission proved a critical turning point. Tasked with escorting Riko Amanai for her merger with Master Tengen, Geto witnessed her assassination by Toji Fushiguro. The subsequent celebration by the Star Religious Group deeply shook him, planting seeds of doubt about protecting non-sorcerers he increasingly perceived as ungrateful and corrupt. This disillusionment intensified. A conversation with Yuki Tsukumo revealed non-sorcerers as the primary source of cursed energy due to their lack of control. Compounded by the death of his junior Yu Haibara on a mission and encounters with human cruelty—specifically discovering the abused young sorcerer girls Mimiko and Nanako Hasaba—Geto radicalized. He concluded that eradicating all non-sorcerers was essential to eliminate curses and create a world solely for jujutsu sorcerers. This belief drove him to massacre over 100 villagers and his own parents, resulting in his expulsion from Jujutsu High and designation as a curse user. After defecting, Geto founded a religious organization as a front to gather followers, whom he called "family," and amass cursed spirits. Adopting the appearance of a Buddhist monk to exploit public trust, his hatred for non-sorcerers, whom he derogatorily termed "monkeys," became central to his ideology. He viewed them as inferior beings perpetuating suffering and openly advocated for their extermination. Despite this, he retained camaraderie with fellow sorcerers and showed genuine care for his followers, particularly Mimiko and Nanako, whom he rescued and sheltered. Geto possessed the cursed technique Cursed Spirit Manipulation, enabling him to absorb defeated spirits by converting them into small orbs and ingesting them—a process described as tasting like "a rag soaked in vomit." This allowed him to summon and control these spirits at will, provided they were unbound or freed after their master's death. Amassing over 4,000 spirits granted him versatile abilities for combat, reconnaissance, and defense. His signature technique, Maximum: Uzumaki, fused multiple spirits into a concentrated blast of cursed energy, though it consumed the spirits permanently. Beyond his cursed techniques, Geto was a master hand-to-hand combatant, utilizing martial arts or cursed tools like Playful Cloud. He excelled in tactical planning and barrier techniques, creating large-scale curtains to isolate battlefields. His strategic acumen shone during the Night Parade of a Hundred Demons, where he deployed thousands of curses across Tokyo and Kyoto to distract jujutsu society while personally attacking Jujutsu High to capture the special-grade vengeful spirit Rika Orimoto. During the Night Parade, Geto confronted Yuta Okkotsu, Rika's vessel. Though initially overpowering Yuta and his allies, Geto expressed conflicted emotions, shedding tears of joy witnessing young sorcerers protect each other—a reflection of his idealized world. He was ultimately defeated by Yuta's unleashed power. In his final moments, encountering Gojo, Geto confessed he could never find happiness in the current world but expressed regret over their fractured bond. Gojo then fulfilled a promise by killing him. Following his death, Geto's body was possessed by Kenjaku, an ancient sorcerer using a brain-transplant technique to control corpses and access their abilities. Kenjaku exploited Geto's Cursed Spirit Manipulation for his own goals, including initiating the Shibuya Incident and the Culling Games. This possession caused confusion among Geto's former allies, with Gojo notably rejecting Kenjaku's control, stating his soul recognized the imposture despite his Six Eyes identifying Geto's physical form. Geto's legacy persisted through Kenjaku's actions and his ideological impact on characters like Yuta. His complex relationship with Gojo remained a defining element, symbolizing a friendship shattered by irreconcilable worldviews yet marked by enduring loyalty.