Beautiful and intelligent, her only flaw is being sleep-deprived, since she doesn't seem to sleep much. Soon after Shido is approached by Ratatoskr, Reine is employed as the new physics teacher at Raizen High School to assist him during his school life. Reine usually gives the best advice or opinions out of Ratatoskr's crew during both the crew's operations to seal Spirits and normal circumstances. Reine is unarguably a beautiful woman with pale skin. She still looks to be in her 20s, despite saying that she hasn't slept in 30 years. She has long, unkempt, pale blue hair which is tied into a right-side ponytail and blue eyes which seem to always be sleepy. Her most distinct feature is the pair of dark circles beneath her eyes. She wears a pair of glasses with a circular frame. Her height is 164 cm, and her three sizes are B95/W63/H89. She is usually or always seen with a small blue teddy bear that fits in her breast pocket. During her duty on Fraxinus, she wears 's uniform, while as a Physics teacher at Shido's school, she wears a long white lab coat over a pink shirt with a rather low V-neck collar, a purple miniskirt, a pair of black stockings, and a pair of blue teddy bear slippers. She also wears a small silver ring on her silver chain necklace. When disguised as , Reine typically surrounds herself with some sort of mosaic that, while people can see and hear her, makes it impossible for people to determine her appearance or the sound of her voice. When talking with Shido after he traveled back in time, she temporarily took on the form of Rinne Sonogami, something which she described as using "another shape". During her brief fight against Kurumi, Reine equips an Astral Dress reminiscent of the one worn by her original self Mio Takamiya. The dress has a translucent color like water droplets and has a noticeable slit that shows off her left leg. The dress itself is decorated with flowers and golden jewelry. Large strands of fabric that are shaped like leaves can also be seen extending out from the Astral Dress. Reine is a very logical, reasonable, and mature woman. Surprisingly enough, and despite her usual cold demeanor, she has proven countless times to be a very sensitive, considerate and understanding person. She is quick-witted enough to adapt to the sudden appearance of the Yamai sisters and seamlessly integrate them into her class field trip without raising suspicions from others. She's also good at giving advice and coaching Shido during his dates with the Spirits, even Kotori seems to take her advice well. Reine is very good with handling children as when Natsumi turned everyone but Shido into children she was able to calm them all instantly. She has also displayed this skill towards Shido himself, calming him down after he recognized Kotori as a Spirit. Shido himself stated that she is like a mother, which she seems to react to in a strange way. She has a tendency to faint suddenly due to her suffering from sleep deprivation. Despite using extensive sleep medication, Reine is extremely insomniac, with herself remarking that she hasn't slept in 30 years. The cause for this is revealed to be caused by PTSD, with her suffering from repeated nightmares of Shinji's death every time she tries to go to sleep. While Reine is normally calm and collected, there are rare occasions when she shows anger. These instances are rare enough that Kotori had never seen her angry until the events of Volume 3 when Reine showed her Mana's body had been heavily modified to give her abnormal strength at the cost of lowering her remaining lifespan to 10 years. When disguised as , she retains her calm and analytic personality, easily deducing that Origami traveled in time solely from her possession of Metatron, which she hadn't given away yet. Here, she appears to have a goal-orientated mindset focused on the fulfillment of her wish to reunite with Shinji. To that end, she has turned several humans into Spirits using Sephira Crystals. To do this, has shown to be willing to use several underhanded tactics. When she turned Kotori into a spirit, she preyed on her desire to stop being a crybaby. When she turned Miku into a spirit, she used her hatred of humanity (especially of men) and her despair for losing her voice. When she turned Origami into a Spirit, she used her desire to obtain power. neglected to mention what Sephira Crystals would exactly do to them. It seems that Shido also fits into her plans somehow, as implied by both Westcott and her actions. She also doesn't appear to like the codename given to her by Ratatoskr, as seen by her displeased reaction when Shido calls her by it. appears to evaluate a person based on their potential as a future Spirit. To that end, she has been looking for talented people to turn them into Spirits. After the Origami from the future attacked the from five years ago and was able to remove her mosaic noise, noted to herself that she couldn't think of not turning a girl with so much talent into a Spirit, despite knowing that she would turn against her one day. Five years before the beginning of the series Reine, while in her disguise, appeared out of nowhere in front of Kotori, who was crying over how both of her parents and her brother were not with her despite it being her birthday. asked her what was wrong, but Kotori, who was told not to talk to strangers, was scared because she couldn't make out 's appearance. then told her that she was afraid of her brother abandoning her because she was always a crybaby, once again getting Kotori's attention because she was seemingly reading her mind. then offered Kotori a red Sephira Crystal and told her that it would make her stop being a crybaby. Kotori touched the gem, which was then immediately absorbed into her and turned into Spirit with the ability to control fire. then disappeared just as Kotori's new powers quickly went out of control and destroyed the neighborhood. After Kotori accidentally injured her older brother, Shido, who had just returned to her, reappeared in front of her and told her that if she kissed her brother, she would be able to save his life. As Kotori did what she was told and kissed Shido, most of the flames immediately disappeared and the rest started to heal his wounds. After he was fully recovered, Shido moved in front of Kotori to protect her from , but assured them that she had no intention of harming them. told them that the ending they brought out was the best-case scenario, but that it may be better to forget about this accident for now. She then placed both of her hands on their heads and erased their memories. A few years later, appeared once again. This time in the presence of Miku Izayoi, who was thinking of committing suicide after her career as a singer had been ruined because of false rumors. Noting Miku’s disappointment in humans, offered Miku a violet Sephira Crystal and told her that it would give her a god-like power that would change everything back in her favor. Miku accepted the gem, and upon touching it, the Sephira was instantly absorbed into her body, transforming her into a Spirit Reine has the ability to disguise herself as by surrounding her appearance with a strange noise that also alters her voice. The mosaic disguise itself can act as a barrier to defend herself from attacks. To wit, it has withstood a concentrated energy beam from and a gatling barrage of bullets from Kurumi before dissipating. She can also freely alter her disguise to appear in the form of Rinne Sonogami. She has also shown to be able to alter people's memories, the Spirit's common ability of flight, and can seemingly read people's thoughts. has demonstrated great deductive skills. While fighting Origami, she was able to correctly guess that Kurumi had used the 12th bullet to send Origami to the past because she had yet to hand out Metatron's crystal. Likewise, she was able to deduce that Shido had also time-traveled from five years into the future by merely looking at his appearance. In Itsuka Disaster, she created an umbrella-shaped wall to protect Shido from being killed by and was able to weaken Shido's Reiryoku by just touching him. When confronted by Kurumi at the end of her date with Shido, Reine has also displayed the ability to summon her own version of Mio's Astral Dress and engage against the Worst Spirit in brief combat. However, in order to access their full power, she has to remerge back with Mio into a single entity again. Through her adventures in the short story Reine Holiday, Reine has displayed a wide range of miscellaneous skills. Among her various abilities, Reine can play the violin at a professional level, act as a foreign translator, land a royal aircraft, and even conduct medical treatment better than the official medical officer for .