Michiru Kaioh, Sailor Neptune, serves as the Sailor Guardian of Neptune, wielding dominion over oceanic forces. Her civilian identity is a 16-year-old prodigy violinist and student, initially enrolled at Mugen Academy before transferring to Juuban High School. Her surname, "Sea King," mirrors her command over the ocean’s depths, while her given name, meaning "rising," echoes her link to tidal rhythms. Poised and introspective, she balances elegance with emotional reserve, often subordinating personal bonds to her responsibilities. This maturity stems from awakening as a Guardian earlier than her peers. Partnered romantically with Sailor Uranus (Haruka Tenou), their alliance spans manga, anime, and musicals. Operating autonomously, they surveil extraterrestrial threats before uniting with the Inner Guardians. During the Infinity arc, they pursue three Talismans to avert planetary collapse, with Michiru’s Deep Aqua Mirror—a tool for precognition, astral travel, and the Submarine Reflection attack—serving as one. Her violin, the Marine Cathédrale, channels hypersonic waves and the Submarine Violon Tide technique, though the latter remains exclusive to manga canon. Her Guardian forms evolve: Super Sailor Neptune dons translucent shoulder armor and a heart-shaped brooch, while Eternal Sailor Neptune’s attire features layered skirts, elongated gloves, and celestial motifs, all powered by her Neptune Crystal. In the Stars arc, she and Haruka strategically align with Sailor Galaxia, sacrificing themselves to later resurrect. Beyond duty, Michiru swims, paints, and curates cosmetics, favoring sashimi but shunning mushrooms and sea cucumbers. She shares a Victorian home with Haruka and Setsuna Meiou (Sailor Pluto), co-parenting the reborn Hotaru Tomoe (Sailor Saturn), reflecting her nurturing loyalty. Design-wise, her aquamarine waves of hair and piercing blue eyes mirror oceanic depths, complemented by teal-dominated attire. Titles like "Soldier of Deep Waters" and "Soldier of Embrace" underscore her protective intuition. In English dubs, her romance with Haruka is reframed as kinship, sparking fan dissent. Yet her narrative steadfastly highlights sacrifice, epitomized by her declaration: "A world without Haruka isn’t worth living in"—a vow tested when facing existential peril to shield her partner.