Aihi

Aihi (藍緋) was Kokuboro's chief scientist who designed all of their human skins and kept track of Princess's health. She was also something of a prisoner: a bug implanted in her by Byaku prevented her from leaving the castle or disobeying his orders. Aihi envied Kaguro because Byaku's bugs cannot control him.

Appearance
Aihi most often appears in her human form: a woman with dark blue hair. She wears a white lab coat, which has a black armband with a white cross pattern on the left arm (all of her subordinates wear this armband in the manga ), a black top underneath, bluish-green leggings, and sandals. Aihi's true form is an enormous, somewhat humanoid blue flower with a large, single eye at the center of her petals, and countless vines for attacking.

Personality
Aihi tends to be quiet and introspective. She is greatly interested in understanding humans, and dislikes her work being wasted or destroyed. Though she is frustrated by her inability to leave the castle, she also displays concern for Hisui, her only subordinate.

History
While living in a forest, Aihi met a sickly man. Despite numerous warnings that she ate humans, he constantly came to visit her, and she allowed him to live because he was unlike any human she had ever seen. He told her that it was fine if she ate him, since his family would never depend on someone like him and he had no purpose in life. When he became too weak to keep venturing into the forest, he trapped Aihi with a talisman and begged her to come home with him, or else they might never be able to meet again. Although she was reluctant, Aihi agreed because he was so insistent. She quickly tired of his excuses as to why she couldn't eat the members of his household, but when she tried to leave, Aihi discovered that the man had put up charms that prevented her from leaving the house. She could only be free again if the man himself removed the charms, or if he died. The man said that he had done this all because he was desperately lonely, and though it would have been simple to eat him, Aihi instead chose to live with him. Over time, she found herself growing fond of him, because he did not see her as a monster. Unexpectedly, the man's older brother died, and because he had been the heir, the family was in need of leadership. The man decided that he could no longer afford to die, and devoted himself to supporting his family, at the eventual cost of his life. Aihi was amazed that a human with such a weak body could be so strong, and fully exploring this power became the core of her research. She also claimed to have posed as a school nurse in the past, which allowed her easy access to children to eat, and where she learned a great deal about the school system.

The Eager Assistant
At a meeting of Kokuboro's leaders, Aihi is commanded to design a more efficient version of the human suit that allows demons to enter Karasumori undetected (even during the daytime, when they would normally be unable to). She allows her eager subordinate Hisui to try on the outdated model, since she was only going to dispose of it otherwise. Kaguro teases him about being weak, and Hisui rushes to Karasumori without permission to prove himself. Aihi reports the incident to Byaku, expecting him to send reinforcements to retrieve Hisui. Instead, Byaku is only interested in collecting data on Hisui's trip, which angers Aihi. Hisui is eventually destroyed by Yoshimori.

Dressing to Impress
Aihi completes the updated human suits and presents them to Byaku, who is satisfied but not impressed, telling her to use them on some subordinates. This annoys Aihi, as it reminds her of Hisui, and she feels the effort she put into training him was wasted. She issues the new human suits (along with clothing and sunglasses to hide their unusual eye color) to the demons chosen to infiltrate Karasumori: Kaguro, Haroku, Sekia, Haizen, and Sanan. Kaguro, however, chooses to use the older Q-Type model, deciding it will be an interesting test for his power. Kaguro asks why Aihi studies humans, and after evading the question a bit, she tells him that they are only research subjects to her.

A Final Chance for Freedom
With Byaku's defeat, the bug he was using to control Aihi is expelled from her body. Just as she decides to escape the castle, Aihi meets Tokine and saves her from a collapsing bridge. Aihi leads Tokine to her lab and tells her to escape. Tokine asks why Aihi saved her, and Aihi says that smelling a human after such a long time excited her, and reminded her of the human she'd once been a companion to. After telling Tokine her history, Aihi shows her the human suits she created. Tokine assumes that Aihi loved the man she knew, which bothers Aihi, and she tells Tokine to escape. Tokine leaves, realizing that both humans and Ayakashi have sad memories. Aihi starts to leave as well, but Kaguro (still in a human suit) stops her and challenges her to a battle. Aihi transforms and gradually overwhelms Kaguro with her illusion pollen, crushing his body with her vines. However, as she begins to leave, Kaguro appears outside of the human suit and stabs her from behind with several swords. He is about to kill her when he senses Yoshimori approaching, and leaves Aihi to die. In her last moments of life, Aihi returns to her plant form and releases many flowers into the air. One reaches the family of her former human companion who recognizes her and welcomes her back (only occurs in the anime, as he is dead in the manga), while another reaches Shion, one of the few surviving members of Kokuboro, and one that Aihi did not despise.

Powers & Abilities
Plant Form: Aihi's true form is that of a large blue flower with an eye in the center and a multitude of vines that make up was once her body. The size of this form can grow tremendously in height or maintain the height of an average human. While in this form she can manipulate the various vines that make up her body causing them to grow and elongate at will at an alarming rate. She commonly uses them offensively to whip or constrict her opponents. Sometimes she would change her face into her plant form just to poke fun at the man she loved.


 * Regeneration: She is also capable of regenerating her vines almost instantly. However, after Kaguro cuts off her vines, she cannot regenerate those which have been cut off, so she grows new vines instead.


 * Illusion Pollen: Aihi can emit a pollen from her head that affects the perceptions of her opponents. She further grows buds upon her vines that bloom and emit a light that further enhances the effect overwhelming the opponent.

Kaguro
Though Kaguro enjoyed teasing several of Kokuboro's leaders, he seemed to take a special interest in Aihi and her research on humans. Aihi also held a certain interest in Kaguro, and she envied his strength, which allowed him to make his own rules. However, as with most of his opponents, Kaguro's true interest was only in provoking Aihi, and once she had the chance to escape Kokuboro for good, he confronted her and forced her into a battle with him.

Tokine Yukimura
Since joining Kokuboro, Aihi had been a prisoner, unable to leave the castle because of the worm Byaku implanted in her head. Tokine was the first human she had met in a long time, and for reasons unknown to them both, Aihi was compelled to save her, despite their being enemies. After Aihi told Tokine her history, Tokine suggested that Aihi was in love with her former companion, an idea that surprised Aihi. As Tokine left, she noted that it was possible for Ayakashi to have human feelings as well.

Aihi's Companion
Aihi once inhabited a forest, in which she met a sickly human. Oddly, though he recognized her as an Ayakashi, instead of being afraid, he was fascinated by her appearance. Aihi allowed him to live on a whim, and the man repeatedly returned to the forest just to see her. As the man's health began to decline, he feared he would lack the strength to journey to the forest, and used a talisman to force her to accompany him home. Once inside, Aihi found herself held prisoner by talisman placed in the house. Still unwilling to eat the man, she remained in his home, reassured that he would not live long. However, once the man's brother died, he resolved to live so he could take care of his family. Aihi was fascinated by the idea that someone so weak could possess such strength. However, when the talismans were cast aside by an unknown entity, it was clear that Aihi's companion either had lost interest in her, or simply didn't care enough to keep her bound in his home. Either way, Aihi took advantage of his carelessness and left. Aihi began to study humans in great detail, allowing her to produce human skin disguises. During her studies (or maybe even before), she fell in love with the humans' ability to create bonds with everything. Without these bonds, she believed, a person has nothing. She never forgot her companion, and his appearance served as the foundation for her human skin disguises.

Etymology

 * The name Aihi means "indigo" (藍) (ai) and "scarlet, cardinal, red" (緋) (hi).