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Michiru Kaiou is the civilian identity and present-day incarnation of Sailor Neptune. This is the original depiction of the manga character created by Naoko Takeuchi.


Elegant, sophisticated, though sometimes cold and capable of sharp anger, she has been described by Usagi Tsukino as 'the ideal princess'.

Michiru attends Mugen Gakuen with Haruka Tenou and the younger Hotaru Tomoe. She is patient and caring, almost always offering a smile or laugh to a situation. While polite and calm to a fault, she is not the most social person, but when she does become close with someone it is because she truly wants to. She dislikes being patronized and will not indulge others.

This can make her look like a snob, and her seeming perfection at everything does not help this perception of her. She is a genuinely intelligent young woman, a prodigal violinist and artist, already famous for her endeavors. Her intelligence is also apparent through her acceptance to Mugen Gakuen, a school with a very high acceptance threshold; only geniuses of some field are permitted enrollment.


Michiru is an extremely beautiful and delicate-looking girl of slim stature and average height, with deep blue eyes and wavy teal hair that falls just past her shoulders. The epitome of elegance and femininity, she has an excellent sense of fashion, being always dressed smartly, and applying makeup or perfectly made up already. Usagi and Minako were both utterly dazzled by her beauty when they first saw her, and Usagi has gone as far as saying that Michiru is exactly what a fairy tale princess would be like.


Infinity Arc

Dream Arc

Stars Arc

Powers and Abilities

Michiru can use her talisman to predict events of a close future.


In concept art, Naoko Takeuchi had planned for Michiru and Haruka to be affiliated with the Takarazuka Revue. In addition, she was originally intended to wear a bow in her hair when at school. Neither characteristic was carried over to the final version of her development.

According to the Materials Collection, she had a kindness "as great as the sea."


Michiru's surname (海王, kaiou) translates to "Sea King", based on the Japanese name of the planet Neptune (海王星 Kaiousei "Sea King Star", the given title of Neptune, the Roman god of the sea).

Michiru's first name means "rising".Her original English name Michelle a French feminine form of Michel, from the Hebrew name Michael meaning "Who is like God?"Her name that was used on the doll box back in the 1990's used by Irwin was Nerissa which means Sea Nymph/From the Sea.


  • Michiru owns her own helicopter that she calls the Kaio Maru.
  • Michiru is capable of using the Deep Aqua Mirror without needing to become Sailor Neptune.
  • Michiru's apartment number in the Infinity arc is "1306". If one removes the "1", they will get "306", the numbers of her birthday. (Michiru's birthday is March 6, or 3-06)
  • As with the other members of the Outer Senshi, her surname is also the name of a rail line in Tokyo.
  • The Sailor Moon "Materials Collection" confirms Haruka to be in her first year of high school at the start of her first appearance, along with Michiru.


Michiru in the Infinity Academy uniform
Michiru in the Juuban High School uniform
Neptune m01
Michiru playing the violin
Haruka and Michiru in the Dream arc
Haruka and Michiru.
HSMHM Profiles Manga
Hotaru, Setsuna, Michiru, Haruka, and Minako's profiles from volume 10 of the tankoban version of the manga.

Tumblr m247xvqGM01r89poho1 500
Michiru in artbook 3. Art by Naoko Takeuchi
Michiru and Haruka in Artbook 3. Art by Naoko Takeuchi
Haruka and Michiru in Artbook 3. Cover of Act 29. Art by Naoko Takeuchi.
All10InnerSenshiBlueAndYellow Artbook 3
All10SenshiSwimsuits Artbook 3
All 10 Senshi as Sailors Artbook 3
All 10 Senshi Artbook 4 Cover
All 10 Senshi in white shirts Artbook 4
All 10 Senshi with blond-brown hair Artbook 4
All 10 Senshi in Swimsuits on Lillypad flowers
All 10 Senshi in Tuxedos
All 10 Senshi in Red
All 10 Senshi in Princess Dresses
The Outer Senshi Artbook 3
Sailor Senshi Artbook 4 Blue
Sailor Senshi Fashionable Clothes
Usagi, her Senshi, and Chibi Chibi
Solar System Senshi and the Starlights School
Sailor Senshi White Dresses
Sailor Senshi in Kimonos
Sailor Senshi Wedding Dresses

Michiru Concept Art
Michiru's concept art

Kanzenban 10
The Inner Senshi on the cover of volume 10 of the Kanzenban manga.


  1. Michiru Kaiou at Sailor Moon Official Website (Japanese)
Sailor Senshi

Solar System Senshi Sailor MoonSailor MercurySailor MarsSailor JupiterSailor Venus/Sailor V
Other Senshi Sailor Luna
Civilian Identities Usagi TsukinoAmi MizunoRei HinoMakoto KinoMinako AinoLuna Tsukino
Allies Mamoru Chiba/Tuxedo MaskLunaArtemis