Isuke Inukai holds the No. 2 rank in Class Black, a recurring figure among twelve assassins competing to eliminate Haru Ichinose for a wish—specifically, securing funds to build a retirement home for her adoptive parents. Born into a neglectful household, she endured tragedy when her younger brother perished due to parental negligence. Her biological parents were later killed by Inukai Eisuke, a neighboring assassin who adopted her as his protégée, training her alongside his male partner, who became her second adoptive parent.

Sporting long pink hair with dual curls framing her face and striking orange eyes, Isuke stands at 160 cm, often elevated by 10 cm heels. Her signature ensemble features a black cropped jacket, purple plaid crop top, coordinating scarf and skirt, and brown high-heeled boots. She exudes a brash, self-centered demeanor, openly prioritizing profit, yet harbors fierce loyalty and generosity toward her adoptive family and fiancée, Sagae Haruki. Though she avoids gratuitous violence, opting for swift, clean kills, she unleashes ruthless efficiency when provoked.

Proficient in hand-to-hand combat and bladed brass knuckles, she supplements her arsenal with firearms and a shrewd understanding of pharmaceuticals, exemplified by her attempt to incapacitate Haru through drugging. Academically disinterested, she frequently dozes through classes, comically oblivious to her consistently failing grades. Her roots trace to Kanagawa Prefecture, with her official adoption date commemorated as her birthday. Post-series, she survives and is seen vacationing with her adoptive parents, lamenting her expulsion from Class Black post-defeat by Tokaku Azuma. Her character arc culminates in a romantic engagement to Haruki, unveiling a tender dimension beneath her abrasive facade.