Yomi Kasuga

"I am the Demon Tamer, my name is Yomi Kasuga. I'm taking over Karasumori."

- Yomi

Yomi Kasuga (春日夜未, Kasuga Yomi) is a demon tamer, and her partner is an ogre Ayakashi named Yoki. She is introduced as an investigator from The Shadow Organization and an ally to Tokine and Yoshimori, but later betrays them and reveals her true intention of using Karasumori's power to make Yoki much stronger. As a child, Yomi worked with Tokio Yukimura (Tokine's father), but inwardly resented him because he reminded Yomi of her own weakness.

Appearance
Yomi typically wears a light violet kimono (and has apparently done so since she was a child) with various colored sashes (obi). The kimono is short, past her knees and right above her calves. She wears light violet zōri sandals. Her eyes are light brown, and her hair is light violet and in the style of a traditional bob that barely reaches her shoulders. She is short and fit, though somewhat small for her age (especially in comparison to other characters in her age range).

Personality
When Yomi was little, she was generally cheerful despite having a strict father. She was very pleased with being given Yoki as a partner, even though others considered him weak, and the two became best friends. However, over time the constant insults from her father and his associates had a negative impact on Yomi's confidence in herself and Yoki. After her father told her that Yoki was weak and meant to be destroyed, she cried in Yoki's hand and vowed to never trust adults again. She despised Tokio Yukimura for telling her that Yoki would get stronger, and believed that he was weak and died for no reason. Yomi has proven to be a talented actress, disguising her true intentions behind a friendly, slightly clumsy facade. She convinced Yoshimori and Tokine to relax around her, then trapped Yoshimori and tried to overwhelm Tokine with Yoki's power. After being escorted away from Karasumori, Yomi still appears to be very cynical and quick to anger much of the time, especially while meeting with Masamori Sumimura, who she claims to hate. However, she is one of the few who notices that his duties have begun to take a physical toll on him, and appears somewhat concerned.

History
Yomi belongs to a demon tamer clan, and as a child she picked an ogre demon named Yoki to be her partner. However, he was considerably weak and brought shame upon her family, which drove her to make him stronger in any way necessary. Yomi's family is related to the Kidoin Clan through questionable means, and are therefore forbidden to bear the Kidoin name. Despite this, Nura Kidoin favored Yomi because she treated her demon with kindness, a quality Nura herself was well known for. As a young girl, Yomi worked for the Shadow Organization, where she met Tokio Yukimura. Though Tokio encouraged her, Yomi came to resent him for what she saw as weakness, and believed that he gave his life for no reason.

Yomi's Plot for Power
Yomi comes to Karasumori to investigate and "check up on" the work of the Sumimura and Yukimura families, claiming that she's just inspecting. She obtains permission to stay at the Yukimura Home, and mentions having worked with Tokine's late father Tokio Yukimura in the past. Both Tokine and Yoshimori come to see her as slightly clumsy, but ultimately friendly and harmless. However, Yomi's true intentions come to light when she betrays them: she drugs Yoshimori and stores him in Yoki's back, then traps Tokine in a pit covered by a boulder with a charm she put on to repel kekkai techniques. Both Tokine and Yoshimori escape their respective traps, and Yoki begins to draw in power from Karasumori. However, because of his pledge ring on his horn, binding him to Yomi, he is unable to surpass his current limits.

Wanting the full transformation, he breaks their contract and abandons Yomi. After transforming for the first time, he attempts to kill Yoshimori. Even then Yomi demands that Yoshimori not get in Yoki's way, but while Yoshimori refuses to let Yoki run wild, he promises Yomi that he won't kill him, much to her surprise. Yoshimori and Yoki fight, and when neither claims victory after a while, Yoki begins transforming again. He is prevented by the intervention of Hakudo and Odo, two operatives from the Shadow Organization, who have come to arrest Yomi for treason. After Yoki's body is destroyed in battle, he regenerates from a piece of his horn into a tiny, powerless form and is returned to Yomi. Yomi is taken away by Hakudo and Odo. Though Yomi is officially scheduled to be executed, Masamori Sumimura negotiates for her punishment to be reduced, and has since employed her as his informant.

Yomi's Investigations
Yomi typically meets Masamori at a diner in order to pass along information. She is able to confirm that Masamori's promotion to the Shadow Organization's executive group is due largely to the Night Troop's Intelligence Unit Head Kei Sazanami, and that this was the work of another executive. Masamori asks her to gather info on them, and though Yomi initially refuses because of the danger, Masamori is confident she can do it because she is related to one of the executives.

Yomi later confirms the identity of the executive controlling the traitors with the Shadow Organization. Masamori admits he already knows, and is on his way to meet the man at the moment.

Masamori recalls Yomi to inform her that her job will become more dangerous, since they are now for the sake of the entire Shadow Organization. Yomi is surprised to learn that Masamori is finally recalling Sazanami, as leaving him unchecked allowed Kokuboro was able to take advantage of them.

A Family Connection
It is later revealed that Yomi is the great-niece of Nura Kidoin, 2nd Seat on the Council of Twelve, and Masamori intends to use this connection to meet with her, so that he will have an ally against the Commander. Yomi warns him that Nura is extremely shy and unlikely to assist him, but gives in when Masamori begs her. Although Yomi is able to arrange a meeting, Nura backs out at the last moment. Yomi apologizes for being useless, but Masamori assures her that she isn't.

Equipment

 * Contract Ring: Yomi possessed a contract ring that she wore while summoning Yoki to do battle (he wore the corresponding larger ring around his left horn). The ring was a charmed tool, and served as both a symbol of their bond and a means of unspoken communication between them. However, when Yoki, tainted by Karasumori's power, turned his back on Yomi, both rings shattered, symbolizing their broken trust.
 * Talismans: Yomi uses talismans to provide minor support for Yoki in combat.

Powers & Abilities
Demon Taming (Ogre Specialization): As a demon tamer of the Kidoin Clan, Yomi commanded her ogre Yoki via a contract ring. Even without the ring, Yomi and Yoki usually know what each other are thinking, though this could either be a result of their close bond, or an aspect of Yomi's ability as a demon tamer. Though Yoki destroyed the ring while under Karasumori's influence, they still maintain a very close bond because of their promise never to betray each other.

Spells: Yomi knows at least some spells, and was able to equip a boulder with charms that repelled Kekkaishi techniques.

Information Gathering: Yomi is very skilled at obtaining information, thanks in part to her ability to seem naturally friendly and slightly clumsy.

Masamori Sumimura
Yomi initially dislikes Masamori: for treating her like a child, inspiring her to go to Karasumori and forcing her to work as his informant. As a result, she is always in a bad mood when they meet, preferring only to discuss business. However, she always notices and is concerned when Masamori is not in perfect health, implying that she cares for him a great deal. It is also implied that she is romantically interested in him since she sends Masamori his favorite treats.

Etymology

 * The name Yomi means "night" (夜) (yo) and "un-, not yet, hitherto, still, even now, sign of the ram, 1-3PM, eighth sign of Chinese zodiac" (未) (mi), which literally means "not at night" altogether.
 * Yomi's surname Kasuga means "spring" (春) (ka) and "sun, day" (日) (suka/suga), which literally means "spring/spring day" altogether.

Trivia

 * Although Yomi's size would make one think she is around Yoshimori Sumimura or Tokine Yukimura's age, she is actually older than Masamori Sumimura. She becomes especially irritated anytime Masamori treats her as if she is a child, immature for her age or younger than him.