Miya is a slender yet shapely fair-skinned woman waist-length purple hair with shorter bangs that is in a hime cut and brown eyes. She wears the traditional attire of a miko that is a purple hakama, a white haori with a sash-like belt, wooden sandals and a white ribbon to partially hold her hair in place. During her time in the Disciplinary Squad, she wore their standard outfit. It's worth noting that, despite being the "oldest" Sekirei, she still retains her same youthful appearance from when she was found on Kamikura Island 21 years prior.
Miya is an unwinged Sekirei as Takehito Asama (Miya's husband) was not an Ashikabi. She is Sekirei #01 and the feared former leader of the first generation of the Disciplinary Squad, although Miya claimed that she was a completely different person in the past during her time with MBI. The one responsible for changing Miya was her eventual husband, who she credits with enabling her to learn about the people and the world which changed her view on life. Though, after some time, she came to suffer as Takehito died indirectly thanks to her actions which resulted in Miya leaving MBI and maintaining the Inn that her husband built, where she would never refuse anyone who needed shelter.
In Izumo Inn, Miya is often described as a mother figure to the others, which is strongly denied by Miya, who states that everyone views her more as a big sister. She looks after everyone, trains Sahashi Minato's Sekirei and was willing to go and kill Minaka if Homura would have simply asked her to. Though she cares about Minato, Miya often enjoys to make fun of him in a slightly sly and teasing manner, throwing several embarrassing remarks in the presence of his own Sekirei and stated that it has become quite lively ever since he arrived. She also has a tendency to listen in on other people's conversations (mostly Minato's) by wiretapping via a rubber duck outfitted with a speaker made by Matsu, whom she christened "Duck-san".
Despite being the caring maternal figure of Izumo Inn, Miya maintains a strict set of rules for her tenants to follow. Under her roof she prohibits fighting obscenity and illicit sexual activity in her house, and has stated on more than one occasion that she will not forgive anyone who uses violence in the inn. When she becomes angry, annoyed, or if someone breaks the rules of the house, and when she is giving threats, (such as evicting Minato and the others if they learn too much about her past), a demonic visage of a hannya appears behind or above her head. The hannya is intimidating enough to scare even Homura and Tsukiumi into submission; in a flashback, it is revealed that Miya's then-eventual husband Takehito used the hannya, and she presumably learned how to do it from him. Notably, it was witnessing Takehito using the hannya that made her smile for the first time. Her strength and the hannya are the sources of her reputation as the "Hannya of the North".
She is very fond of all of Minato's Sekirei and has even said that she thinks that they are too good for him, despite Matsu's objections. Miya has even fought together with two of Minato's Sekirei, Matsu, and Kazehana when they were all in the disciplinary squad together.
Abilities and Powers
Miya specializes in swordsmanship and is strongly implied to be the strongest Sekirei, even referred to by Karasuba as from "another dimension" (Yume, Karasuba's workmate and rival, only garnered "foul player"). An indication of her power is shown when she became the first leader of the Disciplinary Squad and was able to sink several ships with just the shockwave from her sword. While having retired from actual combat, Miya does still regularly practice to keep her skills fresh. Miya has incredible speed as seen when she spars with Tsukiumi. Matsu once stated that if Miya and Karasuba would engage in a fight, half of Tokyo would be destroyed in the process. This alone shows the potential power of her and throughout the manga, she is referred to along with Karasuba as the strongest Sekirei, and not even MBI dares to meddle with her. She once owned the legendary Totsuga No Tsurugi, a longsword, but threw it away when she left MBI.
As the Sekirei Queen, Miya has absolute control of Kouten and can command it to do anything even if she is not present on it. When a Norito-enhanced Matsu took control of it, she was only able to command it for about a minute before Miya took control back. 
Miya was the leader of the first generation Disciplinary Squad and participated in defending Kamikura Island. At some point, she engaged in a relationship with Takehito Asama (calling him her husband) and left MBI to settle down in Izumo Inn. In the beginning of her stay there, she couldn't handle the housework at all and Seo Kaoru helped out. She then was taught all that was necessary, something that even she acknowledges.
Miya is first introduced after Musubi and Sahashi Minato fall from the sky. She lends them clothes and has Homura patch up Minato after the fall. Minato then explains to her that he got evicted from his apartment and asks if can stay at Inn. Miya tells him that her husband never believed in turning away someone in need, and that maybe its the clothes make him Minato look like her husband and allows him to stay. Kagari asks her if its smart to just decide on taking in strangers who suddenly fell from the sky, and she replies that if they got here by chance, then it was the guidance of the gods. She then invites him in to talk about the details.
Miya is seen next after Minato and Musubi move into the Izumo Inn. In a flashback chapter, we see Miya training in the courtyard of the Inn, Musubi instantly asks her to spar which she agrees to. After a quick loss, they eat breakfast after training with Musubi. She and Musubi give a call to Minato who forgot his phone. She waves off Musubi, giving her a little bit of advice before going, when she goes to return Minato's phone.
She is later seen when Kagari returns to the Inn after protecting the Green Girl Kusano from Akitsu, he tells Miya to prepare an extra plate, much to her shock. When Minato returns to the Inn, Miya instantly thinks the worst, threatening him with her blade. Afterwards, Minato lied Miya by telling her that Ku is his relative that he has to take care of. When Ku passes out after eating, Miya insinuates to Minato that he is a pedophile after he tells her he can't trouble her with Ku sleeping in her room.
Miya hides her identity as a Sekirei from others. Only the other members of the 'first generation' Disciplinary Squad and Homura (#06) know her true identity. When Minato asked about #01's whereabouts, Miya answers that she died along with Takehito. When she saw the honest feelings of Minato and his Sekirei about Uzume's death, she was suddenly forced to make her move and give up neutrality in the Sekirei Plan, so she revealed her identity to Minato and the others, calling herself a being neither human nor Sekirei but more like a goddess. She is the only Sekirei to have a family and a family name.
She is revealed to be the final opponent to beat in the sekirei plan.
Anime and Manga Difference
- In the anime, Miya is the person who convinces Tsukiumi to help Minato in the escape plan.
- In the manga, she also seems to be less hostile to Minato.
- Sekirei Manga chapter 73
- Sekirei Manga chapter 19
- Sekirei Manga chapter 71
- Sekirei Manga chapter 18
- Sekirei Manga chapter 62
- Sekirei Manga chapter 100
- Sekirei Manga Chapter 150
- Sekirei Manga chapter 166
- Sekirei Manga chapter 118.5 (Young Gangan Big Issue Vol3 2011)
- Sekirei Manga chapter 110
- Sekirei Manga chapter 111