Kurumi Nonaka

Kurumi Nonaka (野中 胡桃, Nonaka Kurumi) is a member of the Tatsuyama Village and the younger sister of Yuki, making her the youngest child of Shuuya and Kaoru Nonaka. She is an Elemental Master with a strong connection with spirits. At first, she appeared as one of the four sent to eliminate the "Suzaku" Aoi, upon joining the Serizawa Residence, she becomes one of the main female characters in the series.

Appearance
Kurumi is a petite young girl who is surprisingly developed for her age with black hair that changes to silver tied up in a ponytail most of the time using a white scrunchy and yellow eyes just like her older sister.

Personality
Kurumi is first shown to be very protective of her older sister and is also dutiful to her position as a hero. She also held no sympathy for Rei or Takashi after the incident from four years ago, even calling Rei a traitor due to a mixture of the grief that it caused her sister, protecting the "failure" of the Sí Xiàng Project, despite her being initially being close to him thinking of Rei as an older brother.

She didn't hesitate to attack Rei in their battle against one another, then even showed to be insulted after he didn't take her seriously as he used to blunt end of a his sword to attack her. However, after Rei saved her from falling and hearing his suffering as he slept upon being knocked out by Yuki, she realized that he was suffering most after the incident out of the four of them. Kurumi started referring to him as "Rei-oniichan" as she had done in the past.

She quickly developed a close bond with those in the Serizawa residence, but Kurumi is described as having a certain innocence, which riles up the succubus instinct in Eros and Lilith into the depths of depravity becoming both a sexual plaything for them yet close friends. This close proximity, however, it also forces her to confront her long-standing feeling for Rei, which at first caused her to shyly use her spirits to simulate a muted dream for her a couple of months in a row.

History
Kurumi Nonaka is the youngest daughter of Kaoru and Shuuya Nonaka, her father being both a longtime friend and comrade of Hiroyuki Serizawa and Hisashi Sumeragi during the previous great war. In their time together in the Tatsuyama Village, she has been around both Rei, Takashi and her sister, Yuki as a lively little sister who even treated him as an older brother as they played with one another at times even spending nights at one another's houses.

In their training in the past, Kurumi's magic was a lot weaker compared to now with her barriers being weak enough for Rei to cut through. Like Takehito, she wasn't around the Shrine Church where the other children including Rei, Takashi and Yuki and adults when Seito, who was possessed by the Vampire God Nosferatu attacked them.

After that incident, Rei, taking the blame for Seito, and Takashi were banished from the Tatsuyama Village, it left his four childhood friends alone. In order to protect her older sister, Kurumi started to train herself harder compared to before to come strong enough, while also developing a hint of animosity towards Rei.

Powers and Abilities
Being a member of the Tatsuyama Village, she had received physical conditioning from a very young age, as such Kurumi attained above average physical abilities well above that of a normal human. Like Rei, Takashi and Yuki, she is able to recover from wounds at an accelerated rate. Kurumi also had an astonishing affinity and innate talent with spirits, able to bend them to her whim, with the longest time that she took to master a spirit being a few days to the point of being referred to as a Elemental Master. Kurumi is shown to be able to put up a fight against Húndùn through using her water spirits despite not forming a Daemonic Pact with Rei and Orcus, then after completing her Belialuin Vow with Rei, she is on par with Celis and Seito.

Element Master: Kurumi is able to borrow the spirits' power to activate magic without using her own magic power through various channels and requires a magic circle to do so. However, it has weaknesses, the main one being it is tied to any nearby strong spirit and will be limited to that one element as in Volume 2, being paired with Takehito who wielded Táowù, it limits her to wind spirits. And if the channel between her and the spirits are removed, then she won't be able to use magic as shown when Rei used Orcus' Daemo Macabre to do the very same thing. Belialuin Vow:
 * Water Magic: She has a natural affinity for water, able to create cyclones, water dragons, and compressed water spears. Kurumi can also create water dragons as a means of transport.
 * Lightning Magic: She can release balls of lightning at intended targets.
 * Wind Magic: She is able to create gusts of wind to attack and ride on top of them, letting her fly. However, it is polymorphous so it can constantly change direction.
 * Gust: The standard wind attacks.
 * Gale: A series of attacks that are repeatedly aimed at the target.
 * Compressed Air: A very destructive, invisible blast of air. It can create a three-meter radius crater on the ground.
 * Wind Barrier: Kurumi is able to erect wind barriers powerful enough to block slashes from Daemon-enhanced sword, albeit Rei used the blunt side. She can also create wind barriers to deprive spaces of oxygen.

Spirit Powers
As a Spirit Magic User, Kurumi has access to a number of different elemental spirits:
 * Undine (Water Spirit)
 * Apsaras (Water Spirit)
 * Nereids (Water Spirit)

Equipment
Spirit Gauntlet (霊操術の籠手, Soul Purity Arts Gauntlet): This is a special device, which Kurumi uses alongside her spirit magic in order to open channels to them and is able to materialize it at will. The spirit gauntlet can also have different gems implanting into it. In Volume XII, she and her sister had to return their weapons after leaving the Hero Clan, but she and her sister asked Florence and Eisheth to prepare replacements afterward.
 * Black Gem: A dark element and high-class spirit from the Underground, which she received from Eisheth in order to utilize negative spirits in that world after being unable to use her normal positive ones. Kurumi soon learned to master this through accepting her romantic feelings for Rei, as well as focusing on her darker side, letting her replenish the demonic spirit's power by having Rei do perverted things to her.

Trivia

 * Her weak spots are her underarms.
 * After the events of volume 9, Kurumi openly refers to Rei as "Rei-niichan"
 * Her first sexual intercourse was vaginal.
 * One of her fondest memories growing up was going to the amusement park with Rei, Takashi, Yuki, Seito, Takehito, and Ryuuoujima.
 * Has a fear of haunted houses.