"She is the Soldier of the abyss whose guardian planet is Neptune. Equipped with the power of water and ocean her appearance and the manner are those of a mademoiselle"
Michiru (Michelle in NA) first appears in the third season, Sailormoon Super with Haruka (Amara in NA). The two mysterious, distant new Scouts are on a mission to get pure heart crystals, which are found inside people with pure hearts. Their mission is to find the three heart crystals which hold the three Talismans that, when combined, summon the Holy Grail that defeats the threatening darkness and save the world. Little do they know that two of the three Talismans are inside of them; Michiru holds the first of the three Talismans, the Aqua Mirror, which is used in conjunction with Neptune's "submarine reflection" attack.
Since the theft of a heart crystal results in a person's death, both Haruka and Michiru are under the impression that acquiring the Talismans means killing three innocent people to get them, something which greatly upsets the conscience of both girls even though they are doing it for the sake of the earth. One major difference one notices between the two girls is that Haruka is much more willing than Michiru to try and accept the sacrifice of three people than Michiru, although Haruka would never kill a human intentionally; in fact, Michiru points out many times to Haruka that Haruka would never be able to sacrifice those she cared for.
At first Neptune was aloof from the Inner Scouts because they were a hindrance to the mission, but Michiru was friendly to the younger girls in civilian form as they didn't know each other's Scouts' identities. After their identities are revealed to each other, Michiru inevitably becomes a bit more distant to the younger girls, although she pretty much acts the same to them, friendly and graceful. Michiru isn't protective of Serena as Haruka is, but she does consider Serena to be sort of a cute little sister, and Serena does in fact look up to Michiru as the type of woman she wants to be.
