Sailor Neptune was the eighth Sailor Senshi introduced in the series. Unlike the original Inner Senshi, she was not awakened by the moon cats in 20th Century Tokyo, but rather awoke on her own. Her civilian identity was Michiru Kaiou, or Michelle in the dub.
She was introduced in the Sailor Moon S season of the anime and Infinity arc of the manga. Sailor Neptune fought alongside her partner and lover Sailor Uranus in defending the Solar System from outside threats. In both versions of the story, she was elegant, sophisticated, capable of sharp anger, and sometimes cold. She was fully dedicated to her duty as a Senshi.
Sailor Neptune was given specific titles throughout the various series, including "Soldier of the Deep Waters," "Soldier of Embrace," and "Soldier of Affinity." Her personality was no different from when she is a civilian, although certain powers are unavailable to her in that form. Her respective element was the sea or ocean (not just water in general like Sailor Mercury).
- Neptune Planet Power, Make Up - Used her Lip Rod to transform into Sailor Neptune (used in Sailor Moon S, SuperS, and Stars).
- Deep Submerge - Sailor Neptune sent a blue-green sphere shaped like Neptune toward her target.
- Submarine Reflection - Sailor Neptune used one of the talismans, the Deep Aqua Mirror, to either reveal an enemy's weakness or attack with a powerful wave of water.
Sailor Neptune's (S) dominant color was sea-green (tiara gem, choker, collar, gloves, skirt, and heels) and her accent color was navy blue (bows). Her earrings were white studs, her collar had no stripes, and her choker had a sea-green gem with gold accents attached to it. Her shoulder pads were the same as the others. Her gloves were wrist-length (rather than elbow length). Her heels had criss-crossing straps up the ankles, like ballet slippers.
Super Sailor NeptuneEdit
After the "Super" upgrade (Stars), her earrings remained the same, her choker had a star attached to it, her collar had one white stripe, the center of her front bow was a heart, she had one translucent shoulder pad, and the back waist bow was enlarged and lengthened. The length of her gloves remained the same.
- Neptune Planet Power, Make Up - Used this phrase to transform into Sailor Neptune.
- Neptune Crystal Power, Make Up - Used the Neptune Crystal to transform into Sailor Neptune.
- Deep Submerge - Sailor Neptune sent an energy blast at the enemy.
- Submarine Reflection - Sailor Neptune used the Deep Aqua Mirror to either reveal an enemy's weakness or send an energy blast.
- Submarine Violon Tide - Sailor Neptune used her violin to send an energy blast at the enemy.
- Galactica Violon Tide - This attack was used by Sailor Neptune when she was under Sailor Galaxia's control in the Stars arc.
Sailor Neptune's first costume in the manga was completely identical to the anime version.
Super Sailor NeptuneEdit
Her brooch changed from a circle to a heart after Sailor Moon first transformed into Super Sailor Moon. After the "Super" upgrade, her costume was almost identical to the anime version, but the length of her gloves extended to her elbows, and the star on her choker had a sea-green gemstone in the center.
After the last upgrade in the Stars arc, her choker was V-shaped and the center of her front bow was a green five-pointed star. She had round light green puffed sleeves with two strips of darker fabric attached to the bottom. Her gloves became longer, reaching to her upper arms. In artbook illustrations, she had sea-green V-shaped wristbands with golden five-pointed stars on them, but they were not present in the manga. Her belt consisted of two ribbons, one sea green and one light green, with two long, thin back ribbons, clipped together by a golden five-pointed star. Her back bow was light green. Her skirt became two-layered, the top layer being sea-green and the bottom a lighter green. Her boots were knee-high and white, and each had a sea-green V-shaped border with a golden five-pointed star at the top. Her tiara gem was a sea-green five-pointed star and her earrings were sea-green, dangling five-pointed stars.
In the musicals, Sailor Neptune was played by Kahoru Sakamoto, Chikage Tomita, Miyuki Fuji, Hiroko Tahara, Sara Shimada, Yuuka Asami, Tomoko Inami, and Takayo Ooyama. Although she did not have her own image song in the musicals, she did share duets with Sailor Uranus in "Chou Bi! Uranus to Neptune" and "Harsh! Saint Cry!!", which acted as image songs for both of them.
Sailor Neptune's sailor fuku in the musicals was faithful to her costume in the third season of the anime. Her collar, choker, shoes, sleeves, glove fittings, and the top layer of her skirt were green, and her bows and the bottom layer of her skirt were blue. Her sleeves were decorated with dark green beads. The ornament in the center of her front bow was a sea-green cross, in the center of which was a golden circle decorated with a ring of green gems. Her choker ornament was a golden cross with a green gem in the center, and she wore golden cross earrings. The trim on her costume and the stripes on her collar were all gold.
- Sailor Neptune seems to be the only one who awoke to her Senshi powers without the help of the moon cats (like the Inner Senshi) or the involvement of other Senshi (like Sailor Uranus or Sailor Saturn). According to her prologue in the Sailor Moon Sailor Stars singles, her memory awoke in the form of dreams.
- Sailor Neptune and her partner Sailor Uranus were the only two Senshi apart from Sailor Moon to be involved in a long-lasting relationship in the canon.
- Some people propose the theory that Sailor Neptune was an active Senshi even before Sailor V and Sailor Moon.
- Sailor Neptune and Sailor Uranus were said to be cousins in the Cloverway English dub of Sailor Moon, causing a stir and jokes of incest among fans.
- In 1998, Irwin released a line of Senshi of the Outer Solar System dolls well before Sailor Moon S aired in North America. On the boxes of the Sailor Neptune dolls, she was given the civilian name "Nerissa."