|“||You're the worst.||„|
|~ Koneko to Issei whenever he reaches a new level of perversion|
Koneko is a petite girl around 15 years of age with white hair and hazel eyes. At the front, her hair has two long bangs going past her shoulders and several loose bangs hanging over her forehead, while the back has a short bob cut. She also wears a black cat-shaped hair clip on both sides of her hair. She usually wears the Kuoh Academy girls' school uniform, albeit without the shoulder cape. In her Nekomata form, she grows a pair of white cat ears and a pair of matching tails, and her eye pupils become more cat-like.
In the anime, during the Rating Game between Rias and Riser Phenex, she wore black fighter's gloves with pink cat pawprints on the upper palm.
At the beginning of the series, Koneko had a cold personality, rarely showing any feelings or emotions, even when she was speaking. She was also the only one in the group who did not get along with Issei, often insulting and rebuking the latter for his perverted nature, although she reveals that she respects him for never giving up. She shows the most concern for her comrades when they are in trouble, often lending her strength in fights. Koneko apparently has a problem with people calling her a midget (although the context of the phrase could be used to be called flat, as in bust size), as shown in her second battle against Freed Sellzen.
At the end of Volume 5, Koneko soon experiences a 180-degree change in personality after Issei helps her overcome her fear of using Senjutsu, and now shows emotions of love towards Issei. Her love for Issei grows so much that, at the beginning of Volume 11, she starts to go into mating season (though this was later stopped by her sister Kuroka). However, she still insults him when his perverted nature gets the better of him (at least when it isn't directed towards herself).
Born as Shirone, Koneko is a young Nekomata who is part of a rare species among her kind, called the Nekoshou. After losing her parents, she and her older sister, Kuroka, were later taken in by an unnamed Devil who reincarnated her sister as one of the members of his peerage. However, Kuroka's power as a Nekomata supposedly soon grew out of control, eventually causing her to kill her master and become a Stray Devil on the run from her pursuers. In actuality, he had planned to harm Koneko, causing Kuroka to kill him in order to protect her younger sister.
Following the incident and the failed manhunt that came after, Koneko was sentenced to death by the Devils in hopes of preventing another incident like Kuroka's from happening. However, Sirzechs Lucifer, one of the Four Great Satans, protected her, and left her under his sister's, Rias' care. Due to the trauma she experienced with her sister's murder and betrayal, she fell into a deep depression, eventually robbing her of nearly all of her emotions until Rias helped her out of it. It was around that time Rias gave Koneko her name, and made her her servant.
Koneko appears in Volume 1, introducing herself to Issei who just came to the Occult Research Club. She later assisted Issei in his attempt to rescue Asia Argento from the Fallen Angel Raynare.
In Volume 2, she and the other club members assisted Rias in her Rating Game against Riser Phenex. There, she manages to incapacitate Xuelan, allowing Akeno to defeat the Rook and the three Pawns that were incapacitated by Issei before being defeated by Riser's Queen Yubelluna, making her the first in the team to lose.
In Volume 3, Koneko followed Issei when the latter attempted to form an alliance with the Church Duo, Xenovia and Irina Shidou, to help them to reclaim the stolen Excaliburs in exchange for allowing Yuuto to break the Holy Sword. When asked by Yuuto and Rias who later found out about the alliance, she says that she doesn't want Yuuto to leave the team and become a Stray Devil. Later when Kokabiel attacks the Kuoh Academy, Koneko assisted in defeating the Cerberus Kokabiel took with him, before Kokabiel himself went to fight the Gremory Team and easily overwhelm them until Vali Lucifer came to retrieve Kokabiel under Azazel's orders.
In Volume 4, Koneko assisted in training Rias' other Bishop, Gasper Vladi, who was recently unsealed, chasing him around with garlic. During the peace talk between the Three Factions, Koneko was subjected to Gasper's time-stopping powers which was used by the Khaos Brigade in an attempt to kill the leaders of the Three Factions and was unable to help.
In Volume 5 when Rias returns to the Underworld for the Young Devils Gathering, Koneko was burdened by the thought of her being the weakest in the team but was afraid to use her Senjutsu at the same time due to the fear of being like her older sister, Kuroka, who killed her previous master, overdoing her training to the point of collapsing out of fatigue. During the party for the young Devils, Koneko meets Kuroka for the first time following the incident that occurred years ago, with Kuroka intending to take Koneko back with her. While initially wanting to leave with her sister out of concern for Issei and Rias, she eventually decided to stay with Rias after hearing Rias' speech that is full of love towards her (she tells Koneko that she is her Rook, and will not let anyone, including Kuroka, lay her hands on her). Kuroka, who could not help but be bothered with that much trouble, then attempted to murder the two of them, releasing a special mist that immobilized both Rias and Koneko. They are, however, saved by Issei who achieved his Balance Breaker on the spot and manages to beat Kuroka until Arthur Pendragon came to call both Kuroka and Bikou to retreat. During Rias' Rating Game against Sona, Koneko faced off against Sona's Pawn, Ruruko Nimura, and defeated her after starting to use her Senjutsu.
In Volume 7, Koneko is seen doing a Senjutsu healing session with Issei, asking Issei to never use the Juggernaut Drive again while telling Issei that there is a faster method to heal his lifespan (which would involve him sleeping with her) but was interrupted by Rias and Asia. She is later seen assisting her group in their battle against Loki and Fenrir.
In Volume 10, Koneko assisted her master in her Rating Game against Sairaorg Bael, where she and Rossweisse team up and fought against Sairaorg's Rook, Gandoma Balam, and Knight, Misteeta Sabnock under Dice Figure Rules. While Koneko and Rossweisse manages to win the match, both Gandoma and Misteeta launch one last attack on Koneko eliminating her from the Game.
In Volume 11, Koneko went into mating season because of her feelings for Issei, but was deemed too young to risk pregnancy. Fortunately, her sister Kuroka was able to seemingly negate her mating season, allowing her the time to reach physical maturity. Her relationship with her sister also improves, after seeing her sister protect her from an incoming attack and agreeing to Kuroka's proposal of teaching her a Nekomata's Senjutsu and Youjutsu. Also, after Issei asks her to recognize Kuroka as her sister, Koneko asks him to make her his bride when she got bigger.
In Volume 12, Koneko, along with the other members of the Occult Research Club, were staying at the Gremory Palace after being at shock with Issei's "death", holding her feelings in until Ravel criticizes her as she finally breaks down in tears. She later accompanies the others to the human world to visit Ajuka Beelzebub to have him check on Issei's Evil Pieces, and was happy to find out that Issei's soul is alive.