Michiru Saruwatari

Michiru Saruwatari ( みちる, Saruwatari Michiru) is a young Bushi girl who was saved by Musashi when she was about to be eaten by an Oni.

Appearance
Michiru is a doe-eyed, beautiful young lady of an average height. She has long, dark hair, which is tied loosely, and also has some distinctive horn-like locks. Michiru has huge golden eyes that can make even Musashi's heart throb.

Personality
Michiru is both solemn and quiet when in the presence of multiple people, giving off the illusion of tranquil fury to those unaware of her true feelings. In reality, Michiru suffers from a severe case of shyness when speaking to more than two people at once, but she has started to open up her heart the day she befriended Musashi.

Awaji Island Recapture Operation Arc
Passing a forest, Michiru was attacked and captured by an Octopus Pot Oni. Musashi's group had similar fate, but Musashi managed to save them. The old man accompanying Michiru then comes to her calling her princess and explains that she is the daughter of Lord Nobumitsu, head of the Saruwatari Bushi under the Uesugi Alliance, and they are heading to Harima port to join the rest of the Uesugi Alliance and slay a Kishin. Due to her Kitetsuki being more suited to pass the forest, Musashi's group join them. As they travel, Musashi attempts multiple times to talk to her, but Michiru never replies. In the end, he gets annoyed and yells at his friends for constantly changing the subject and not letting him have a conversation with Michiru, which surprises Michiru that he remembered her name. Due to the bumpy road, Musashi and Michiru end up falling off the Kitetsuki and right off a cliff, but Michiru uses her sword to create a flying umbrella and save them. Musashi finds her sword amazing, which reminds Michiru of her father, who had said the same thing. Michiru then explains that she is too shy and didn't knew how to join the conversation, which makes Musashi happy that she wasn't mad at him. She invites him to come with her, but Musashi explains he is headed east. Michiru then reveals he won't be able to reach far and points at a large black wall to east, stating its the Black Kishin, the first oni to set foot in Hinomoto and it has grew so much that it covers half of Hinomoto now. Michiru and the old man then continue on their own.

Michiru reports to her father, Yataro, who asks her if she remembers her true duty to find the Obsidian Goddess host and kill him. Michiru confirms, but states she still haven't found him. Yataro tells her she will know who he is once she meets him, as their stones will reach to each other. Yataro expects great things from Michiru, since she is his most capable daughter. Michiru recalls how Yataro was annoyed he was only creating "garbage", and how she was considered as such and cast aside, with no name or worth. However, she managed to wield a Kitetsu Blade and Yataro praised her for being special and named her Michiru, which characters "three" and "thousand" since she is his 3000th daughter. As she gained value and not wanting to become worthless again, Michiru wish to accomplish her mission. Michiru's caretaker tell her she needs to kill Musashi soon, before Uesugi realizes the Goddess is here. Michiru knows that and states she will kill him before that happens. Michiru observes Musashi training with Katsumi and notes that no one had discovered the Goddess inside of him, so they can still be together. The moment they met, she knew he is the one she must kill, but as she started to fall in love with him, she doesn't want to.

Musashi asks Michiru to send her Blade Energy and connect to him. Wondering how it will feel, she agrees. Moments after their energy connects, black crystals start to come out from both of their bodies. Michiru realizes this is what Yataro meant when he said their stones will reach out. However, Yataro will now know where they are and Michiru feels they need to run. As Michiru and Musashi had turned into a flying black crystal, Kuroko Usami uses her Kitetsu Blade to cast a prison and stop them. Michiru and Musashi return to normal and Michiru stands over Musashi, wanting to protect him. Kuroko tells Tatsuomi that Michiru is someone she marked as possible spy for the black dogs and there are doubts that she is the Saruwatari princess. Michiru realizes that if they look at Musashi, they will discover the Goddess. Kuroko has an idea and shares it with Tatsuomi. Tatsuomi then announces they found an enemy spy and points to arrest Musashi. Michiru is surprised, but promises to help Musashi and later contacts her father.

Kitetsu Sword
Ruri Renge (, Lapis Lazuli Lotus Flower): Michiru’s sword has a dark blade and a butterfly shaped guard on the hilt. When her sword is activated, it manifests many smaller blades, which are arranged similar to an umbrella. She can use it to float in the air, just like when she saved Musashi when they fell off a cliff, and for defensive purposes as well.

Abilities
As far as it has been depicted, Michiru seems to be a very decent swordswoman whose skills have yet to be fully seen other than her masterful use of Ruri Renge for defensive purposes.

Musashi
After being saved by him from a Green Oni, Michiru developed a romantic crush on Musashi and would later confide him about her severe case of shyness. Musashi, on the other hand, was thankful she was the first young woman who would make her heart beat faster.

Etymology

 * The name Michiru means "Three Thousand Treasures".
 * Michiru is written in hiragana (みちる), which has no special meaning. However, when written in kanji (満, 充, 実, 道瑠, 満留, 美智留 or 実千瑠), it could possibly mean:
 * 満 - "full/fullness, enough, satisfy".
 * 充 - "allot, fill".
 * 実 - "fruit, good result, truth".
 * 道瑠 - "path" (道) (michi) and "lapis lazuli" (瑠) (ru).
 * 満留 - "full/fullness, enough, satisfy" (満) (michi) and "detain, fasten, halt, stop" (留) (ru), which literally means "full stay" altogether.
 * 美智留 - "beautiful" (美) (mi), "wisdom, intellect" (智) (chi) and "detain, fasten, halt, stop" (留) (ru).
 * 実千瑠 - "fruit, good result, truth" (実) (mi), "thousand" (千) (chi) and "lapis lazuli" (瑠) (ru).
 * Michiru's surname Saruwatari means "monkey, ape" (猿) (saru) and "transit, ford, ferry, cross, import, deliver, diameter, migrate" (渡) (watari).

Trivia

 * The Saruwatari clan crest resembles one of the many family crests belonging to the Shimazu, the key difference being that, rather than a crane atop a cross, her crest depicts a butterfly beneath a cross.
 * Even though she was not introduced until Chapter 44, somebody looking similarly as Michiru appeared on Chapter 18 as part of a fantastic scenario in which Musashi got married before Kojiro.