Kuroka

Kuroka is a Nekomata and a member of the Vali Team previously belonging to the Khaos Brigade. She is the older sister of Koneko Toujou, and an SS-Class Stray Devil who is one of the Underworld's most wanted criminals.

Appearance
Kuroka is a voluptuous young woman with long black hair with split bangs and hazel eyes with cat-like pupils. Her outfit consists of a black kimono, a yellow obi, a set of golden beads, and an ornately detailed headband. The kimono features a red interior and it is open at her shoulders, giving view to her large breasts which rivals Rias and Akeno in terms of size (Issei describes her breasts as being "well-balanced", sharing the softness of Akeno's and the elasticity of Rias'). In her Nekomata form (which she is mostly in), she grows a pair of black cat ears and two black tails.

Personality
Kuroka has a very playful personality and loves to tease people, using her beauty and sensuousness as a weapon in her arsenal of teasing. Kuroka loves her little sister Koneko dearly, though she seems to have trouble showing it at times, preferring to tease her.

She has expressed an interest in having strong children, having propositioned both Vali and Issei who both have Heavenly Dragons inside of them. It is hinted that the reason as to why she wants to have strong children is because she wants her species to bloom once again, as their species is currently on the brink of extinction.

Adding to her feline personality, Kuroka often ends her sentences with "Nya" (にゃ), mimicking a cat's meow.

History
Kuroka is the older sister of Koneko (then as Shirone) who was born to a rare species among the Nekomata, called the Nekoshou. After losing her parents, she and her sister were later taken in by an unnamed Devil, and she was reincarnated as the Devil's Bishop using two Evil Pieces.

While serving her master, she became extremely talented in Senjutsu and Youjutsu, and her magical power as a Bishop became so great that she surpassed her own master in terms of magical power alone. This later became her undoing when she later became a Stray Devil after she killed her master, with everyone assuming that she was drunk with her own powers, but the real reason being to protect her sister from her master, and became the cause of her sister's near-execution and depression as well as the reason why she refuses to use Senjutsu and Youjutsu. Following the incident, she became one of the Underworld's most wanted criminals, ranking at SS-Class. At some point before the series, she joined the Khaos Brigade.

Birth of the Breast Dragon Emperor
Kuroka appears in Volume 5 during the Young Devil's Gathering alongside Bikou, attempting to take her sister despite Vali's orders and Bikou's warnings. She was then confronted by Issei and Rias, and fought the former after incapacitating Rias and Koneko with her poison mist Youjutsu, knocking down Issei in just two hits. However, the tides were turned when Issei poked Rias' breasts to achieve his Balance Breaker. After being warned by Issei who stops his fist before striking her, Kuroka retreats from the battle with Arthur Pendragon covering her and Bikou's escape.

The Heroic Oppai Dragon
She reappears in Volume 7 alongside her Vali Team teammates in a temporary alliance with the Gremory Team to battle Loki and Fenrir. Prior to the final battle, she asked if Issei is interested in having a sexual relationship with her mainly because she wants his "genes" for strong babies, which she tried with Vali but he denied. During the final battle, she was the one to transfer Vali and Fenrir to a different place in an attempt to capture Fenrir.

In Volume 11, she, Fenrir and Le Fay Pendragon acted as Ophis' bodyguard in the Hyoudou Residence, negating Koneko's mating season. During the attack by Cao Cao and Georg, Kuroka and Le Fay used a magic circle to switch Vali and Fenrir's position, allowing Vali to join the fight. Kuroka, however, was injured while protecting her sister after Cao Cao redirects Vali's attack to Koneko. While recuperating from her injury, she reveals to Issei that her previous master was a power-hungry person who would make even his blood relatives go through crazy power-ups, and intended to use Koneko as an experiment to test the power of a Nekomata, therefore Kuroka was forced to kill her master to protect her sister. She later proposes to teach her sister the Nekomata's Senjutsu and Youjutsu, and is somewhat surprised when Koneko agreed.

In Volume 12, she and the rest of the Vali Team were hiding in the Gremory Palace while waiting for Vali to recuperate from his curse that he received from Samael. She and the rest of the Vali Team later goes to the Realm of the Dead and started a fight with the Grim Reapers under Hades.

The Legend of Oppai Dragon and his Lively Companions
She, along with Le Fay Pendragon, later move into the Hyoudou Residence in Volume 14 as semi-permanent residents so that she could teach her sister on how to use her powers better while making a mess out of Issei's house (much to his dismay) with Le Fay apologizing for Kuroka's actions. After seeing Kuroka reading a book regarding Senjutsu to teach her sister, Issei asked if Kuroka wanted to reconcile with Koneko but Kuroka feels that she did something horrible to her sister even if it was to protect her as she was blamed by many Devils and was even nearly executed. Issei reassured her that he would help the two sisters patch up their relationship when the time comes, adding that Koneko's smile was the most important thing to him. Kuroka finally understood the reason why all the girls around Issei were falling for him, claiming that he was more charming than normal handsome men.

Powers & Abilities
Aside from her enhanced magical abilities as a Bishop, Kuroka is a skilled Senjutsu and Youjutsu user, being able to create mirage copies of herself to throw her opponents off and combining both her techniques to fire concentrated blasts of energy. She can also create a poisonous mist to restrain her opponents (Dragons, however, are immune to it), and can also use Senjutsu to conceal her presence from other Devils by changing her ki flow. She is also capable of performing space-time manipulation, though at this point she can only manipulate space.

Trivia

 * Kuroka's body measurements are B98-W57-H86 cm. (B39-W22-H34 in.) and her height is 161 cm. (5 feet 3 inches), as stated in an issue of Dragon Magazine. Her breast size is recorded as the third largest in the series, behind Rias Gremory and Akeno Himejima.
 * Kuroka's name means "Black Song", in reference to her hair and tail color.
 * In one of the illustrations from Volume 7 of the light novels, Kuroka's ears were colored white instead of the original black.
 * Kuroka appears to not wear any clothing underneath her kimono.