Kaiou Michiru is 16 years old when she and Haruka first meet the Inner Senshi. She is Sailorneptune. She discovered her destiny before Haruka, and she was the reason Haruka accepted her destiny. She had actually wanted to meet Haruka before she had discovered that Haruka was Sailoruranus. Michiru had seen Haruka racing and decided that she wanted to go for a drive with Haruka. She is in love with Haruka, and has been since she first met her.
Michiru did not want her destiny. She wanted to play her violin and paint. However, she was glad to discover that Haruka was Sailoruranus.During the battle in which Haruka became Sailoruranus, she admitted her feelings for Haruka. This is what helped Haruka decide to become Sailoruranus.
Michiru loves to paint and play the violin.Her first year of high school was spent at Mugen Gakuen High School, with Haruka. She was able to enter because of her musical talent and her painting ability. She and Haruka entered the school in order to work undercover because of their mission to find the talisman. They were suspicious of the school, believing it to be behind the daimon attacks. Her second year was spent at Juuban High School. During that school year, she received her power-up from Hotaru with Haruka and Setsuna. She is able to transform into Super Sailorneptune.