Dolphin Mii

Mii has wavy, shoulder-length blond hair. She is tall and slim, with dark blue eyes with a violet hue.

Mii is very helpful and loyal to Saori Kido, whom she reveres and serves in any way she requires. With a kind and gentle personality, Mii is very feminine and elegant, and well-versed in protocol.

Nothing is known about her past or family, everything that happened in Mii's life before she became a Saintia is unknown. Mii was one of the five young girls selected by the Kido Foundation to become Saints in service to Saori; The foundation used the excuse (to separate them from their families) that it was an elite program, in which they selected a small group of young women from all over the world to receive a special education that would guarantee them important positions at an international level. At the Saint Academy, she met Xiaoling, Katja, and Kyōko, her friends and training partners, as well as those who would become the future Saintias in the service of Saori Kido. In the present, Mii is the secretary, guardian and lady-in-waiting of Saori Kido, with whom she maintains a small chat about the latter's concerns, later upon arriving at the private institute "Meteoro", Mii meets Shōko, who intended to meet with Saori to ask her about the whereabouts of her older sister, however she is repelled by Mii without any effort, shortly after this a university sister asks Shōko to leave that place, Mii intervenes stating that she should be considerate of her, since she had been abrupt with the young girl, saying goodbye to Shōko with a "Take care". After Kyōko and a Dryad's battle, Mii appears there wearing the Dolphin Cloth alongside Athena. At the Kido Mansion, Mii meets with Shōko apologizing to her for the way she treated her earlier, but they are interrupted by a new Dryad attack.

Both fight against the invaders, Shōko hits one of her enemies showing off her combat skills but that was not of much help, at that moment Mii demonstrates her strength by defeating all the invaders with a single blow.

The young girls are surprised by the arrival of Atë (who was searching for the one who would be her mother's Yorishiro), who had previously defeated Kyōko, Mii tries to protect Shōko but is easily defeated by Atë. When Athena was about to capture Shōko, Saori appears to help them, Athena begins to attack her but at that moment Mii and Kyōko rejoin to protect her, even when both Saintias unite their cosmos they are easily knocked down, Saori begins to face her enemy, but Athena takes advantage (because Athena has reincarnated as a human therefore she has not yet acquired her full strength of goddess), before she is defeated appears before her the Cloth of Sagittarius to protect her, the Cloth takes the image of Aiolos and shoots the Golden Arrow at Athena, wounded by Athena's attack tries to make the soul of the Goddess Eris take over Shōko's body, but is saved by her sister Kyōko who throws herself between her and the soul of the goddess, taking Shō's place as the Yorishiro of the Goddess Eris; while Mii, Shō and Saori watch as Kyōko is possessed by the soul of the goddess and leaves with Atë.

Mii was chosen to escort Shō to Mummy Mayura on Togakushi Mountain to begin her training to become a Saint, and to carry her sister's Cloth in order to free her from the control of the goddess Eris; During the car ride, Mii explains to Shōko about the Saints and the training she is about to undergo, criticizing Shōko's rude behavior at mealtime, Mii explains that training to become a Saint does not only consist of training fighting skills but also must acquire a special education as a Saintia, much to Shōko's surprise, although Mii advises her that at that moment she should only worry about perfecting her fighting skills as soon as possible, explaining that Saori has given her the special mission of becoming a Saintia.

Shōko questions her life, asking Mii why she was chosen as a yorishiro of the goddess Eris, she explains that it is the will of the gods who choose that, and there is nothing they can do to change their destiny, hearing this Shōko is determined to change that fate and save her sister. Upon arriving at the gates of Togakushi Mountain, Mii says goodbye to Shōko, but not before warning her about the rigorous training she is about to undergo, and although it took them five years to complete, if she wants to save her sister with her own hands she will have to develop the necessary strength as soon as possible since the awakening of the goddess Eris is approaching, despite Shōko claims to already know that, Mii gives her a quick explanation of the cosmos showing her power with a stone; She explains that in that place they train in such a way that some have been able to surpass the Saints, but the training is so hard that he could lose his life, if he wants to turn around and withdraw that was the moment, Shō tells him that he will go anyway, before leaving Mii gives him the message that Saori had given him, in which she says "successfully fulfill your task and make sure you return safely", she mentions that they did not have to tell her something so obvious, in the end Mii says goodbye wishing her luck.

Upon returning to the Kido Mansion, Mii heads to where Saori is to inform her of her return, upon arrival she meets Jabu (who had returned from his training with the Unicorn Cloth) with Saori, she asks Saori if she is a Saint, to which she answers that yes, although the whereabouts of ninety of the hundred young people sent is unknown to them, and there is no way that all of them have managed to become Saints, Saori changes the subject and asks about Shōko, Mii tells her that she is very determined and shows no fear, and asks if she regrets having let her go, after all the path of a Saint is always accompanied by death, to which she responds that since her desire was so strong she had no choice but to let her try to get what she wanted with her own strength or perhaps she just wanted to respond to the hearts of those sisters who both said "I will protect my loved one" and this is what is called the strength of humans or maybe at that moment she wants believe in that.

While Saori watched in the sky as the Evil Seeds dispersed throughout the world, she appears to warn her about the meteor shower, Saori mentions that these are the Evil Seeds that increase the evil that lies in the hearts of humans, and that the power of the goddess Eris began to cover the world, but before it fully awakens they must find powerful Saints to help her face evil, Mii agrees, although she shows concern for Katja who should have met with them two in that place, but they have not had any news from her. While having lunch with Saori, he notices that she did not look well, asking her if it was not too stressful everything that was happening and the preparations for the Galaxian Wars, to which she replies that she was fine, Mii with a smile on her face, tells her not to worry, since they trust in her and that justice will prevail; Just outside the mansion, Emony is watching Mii and Saori from a tree. Later, during Jabu and Toki's battle, while Emony excitedly watches the fight from atop a tree, Mii appears behind Emony, stating that watching from above is rude and that she was going to educate him. She quickly dresses in her Dolphin Cloth and begins a battle against the Dryad.

Before starting the fight she warns Emony that all evil beings who seek to increase Miss Saori's worries will not be forgiven, even when her opponent mocks her she responds by attacking without hesitation with her Angel Splash, when she believed she had defeated her opponent, Emony appears behind her back mocking her and wearing this time her Leaf, stating that they will continue playing, while attacking with her Nightmare Scheme, at that moment Mii is enveloped by her opponent's technique, while she begins to lose her strength little by little, Emony begins to mock Saori, this angers Mii who tells her to be silent, while covering her opponent with a ring of water to immobilize her, she explains that Saori is a goddess who was born as a human and that is why she fears the memories of her eternal battle since the mythological era and yet tries to protect humans with her love, that is why her duty is to protect her noble heart, at that moment she activates her Heaven's Maelstrom with which she destroys the Dryad ending the fight. Mii was present at the moment when Eris (in Kyōko's body) arrived at the Kido mansion, and while the fight was taking place, she was comforting Saori. After Shō's departure, Mii tells Saori not to worry, because she will take care of her return, promising it to Saori. Mii arrives at the moment when Sho was safe, she tells her that she was rescued by a Golden Saint: Milo of Scorpio, given Sho's condition, Mii tells her that she will take care of it and that Sho must retreat, to which the Lesser Horse Saint refuses, saying that she wants to prevent Milo from killing her sister Kyoko, which would have to happen to defeat Eris.

The Saintesses, Xiaoling and Mii, are trapped inside the Temple of Eris. Emony takes Mii prisoner inside the Temple of Eris, in her private garden, seeking to face her old enemy once more. The Dryad manages to defeat and knock Mii unconscious, and plans to place an Evil Seed in her body, so that she takes her to Athena turned into a Dryad, before she can approach, Emony realizes that Mii summoned a water barrier to protect herself, but being so weak the barrier does not pose any problem to her, at that moment she watches as the water turns to ice with the arrival of Katja. The young woman introduces herself as Katja, upon hearing her name, Emony realizes that she is a friend of Mii, and begins to mock her by asking if she had come to save her friend, Katja responds that she came to fulfill her duty and fight for the well-being of Athena. Looking around Katja realizes that the scent of the garden's flowers dulls the senses and casts illusions upon the victim, which is why Mii fell unconscious so easily. Katja freezes and destroys the garden. Seeing this, Emony angrily replies that it was her favorite garden and her dress is destroyed to reveal her Leaf. Emony prepares to fight Katja, but Mii regains consciousness and yells to wait as she is that girl's opponent. She insistently asks Katja to keep going. Seeing her partner's determination, she accepts. Emony tries to stop her but Mii uses a water ring to trap her and Katja continues on her way through the Temple of Eris.

•Delphinus Bomb: Raises one of his arms with his hand open and creates a sphere of water in the sky above him, which he launches thunderously at his opponent. When the sphere hits its target, it explodes brutally, just like a real bomb. •Angel Splash: Mii focuses her cosmos on her legs, to hit her opponent with a violent reverse kick, putting all her strength and balance into her left leg. •Angel Blow Splash: Mii concentrates his cosmos and with a half kick back, hits his opponent with a violent reverse kick, putting all his strength and balance into his left leg, as well as his left arm folds it towards his chest and the left arm is free to maintain balance. •Heaven's Melström: is a technique used by Mii, which consists of Mii concentrating his cosmos in his legs, to perform a kick that releases a powerful upward burst of water with bubbles as if it were a whirlwind, which destroys his opponent.