Aoi (葵) is a clone produced using Kurei's and Kurenai's genes. Due to his inability to generate flames, he is deemed a failure and feels incredibly jealous towards the only 'successful' clone, Renge. He wields a gun, but his true strength lies in the madōgu, Shinryo Shikō, which enables him to alter one's memory. He also wields a sword attached to his right hand, but it is unknown if this is an unnamed madogu, or simply a basic weapon.
Aoi's physical appearance is rather androgynous, as he easily passes for a girl while disguising himself at Nashikiri High. Even his regular attire appears more feminine, and Recca only finds out that Aoi is male by Aoi's own admission. This androgyny likely stems from Aoi being a clone created from Kurei and Kurenai's DNA.
Aoi has dark blue hair and red eyes, and his regular outfit is white and blue.
As one among many of Kōran Mori's attempts to create an artificial flame user, Aoi was unable to produce flames and was created mentally unstable, causing Mori to deem him a failure. However, Mori twists that to his favor by blatantly doting on Renge, whose childish mindset made her easy to control and fueled Aoi's jealousy. In a desire to be recognized by Mori, Aoi does anything Mori wishes of him, including betraying Yanagi and erasing her memories.
Aoi also harbors insecurity over being a "fake" human as a result of being a clone, and likens himself to a deep-sea fish that can't surface to the normal world. He hides those insecurities with a facetious smile and taking pleasure in teasing allies and enemies alike. One of the few people he gets along with is Hiruko Shiten, whom he works together with constantly and comes to view as a friend.
Part in Story
Sealed Lands arc
He first appears in the Sealed Lands, where he easily defeated an injured Tokiya Mikagami after the latter emerged victorious against Mokuren and Mikoto. After Rasen loses the will to fight, Aoi replaces him as the leader of the Ura Uruha.
He eventually transfers to Nashikiri High School in order to befriend Yanagi and the others. This is because his mission was to kidnap Yanagi and erase her memory so that she could be 'absorbed' by the Tendō Jigoku, and the Shinryo Shikō can only tamper with the memories that both the target and the user are aware of. Yanagi's kindness to him makes him doubt his loyalty to Mori.
In Heaven or Hell, Recca finds him in his control room, where there is a window to show deep-sea fish. After Recca finds out that Aoi is a boy and not a girl, he declares that he's glad, because it means that he doesn't need to hold back. The two duel, with Aoi confessing his jealousy over Recca's flames and his desire to be "normal." However, Recca rebuts his notion of being unable to be normal, mentioning Yanagi's friendless past and how she didn't wallow in self-pity like Aoi was. Recca defeats Aoi, and advises Aoi to take his own step forward if he wants the change he wants. After Recca leaves, he and Hiruko, who went to check up on him, decide to defect from the Ura Uruha to help destroy Tendō Jigoku.
After Tendō Jigoku is destroyed, he stays at Domon's house and helps out at the Ishijima Flower Shop.
Shinryo Shikō (神慮思考, Divine Thought): An armband endowed with three crystal spheres. It allows the user to alter memories, given that he or she knows the memories to be altered. It can only keep a certain amount of memories altered, regardless on how many people it was used on. So in order to use the Shinryo Shikō on a new memory, some of the old memories it altered might need to be returned to their previous states.
He also has an unnamed madōgu that takes the form of a collapsible arm-blade. The base of the blade is capable of splitting into prongs for defensive use.
Also, unlike most of the characters that use madōgu, he also uses a gun.