Kokichi Muta, alias Ultimate Mechamaru, commands his battles remotely as a Kyoto Jujutsu High second-year via a mechanical puppet, a necessity imposed by his congenital Heavenly Restriction. Born with a fragile body stripped of his right arm, paralyzed legs, and hypersensitive skin that burned under sunlight and seared with unrelenting pain like countless needles piercing his flesh, his suffering forged a reservoir of colossal cursed energy and unparalleled reach for his Puppet Manipulation technique. This allowed him to pilot Mechamaru units nationwide.
His primary puppet, Ultimate Mechamaru, mirrors a humanoid teenager with sleek robotic armor, armed with cursed-energy weaponry: palm-mounted heat blasters, concealed arm blades, and energy shields. Enhanced combat modes—Mode: Albatross and Mode: Absolute—unleash devastating tactics, including the Ultimate Cannon’s triple-tiered energy barrage and the New Shadow Style: Simple Domain to disrupt enemy Domain Expansions.
Bitter over his physical confines, Kokichi envied Panda’s autonomy as a sentient cursed corpse, masking his simmering resentment behind a detached, mechanical facade. Desperate for freedom, he struck a covert pact with Mahito and Kenjaku via a Binding Vow, trading strategic intel for a healed body while demanding Kyoto students’ safety. Once Mahito’s Idle Transfiguration mended his flesh, Kokichi swiftly turned against them, channeling 17 years’ worth of stored cursed energy into a fierce assault. Though his tactical genius nearly drained Mahito’s reserves, the sorcerer’s Domain Expansion crushed his rebellion, sealing his fate.
Kokichi’s legacy endured through pre-programmed Mini-Mechamaru drones, which relayed critical warnings of Satoru Gojo’s sealing and bolstered allies during the Shibuya Incident until their power faded. A bonus manga panel captured a fleeting, tender mishap: his puppet unintentionally clasping hands with Kasumi Miwa, echoing earlier hints of concealed affection.
His surname—combining “bestow” (与) and “fortune” (幸吉)—reflects both his immense gifted energy and tragic yearning for normalcy. His parents, ordinary civilians deceived by Jujutsu authorities, mourned him years before his true demise, unaware he lived on through steel and cursed machinery.