Shiki is a first-year student at Gessen Girls' Academy, initially projecting a carefree, sociable image with valley girl speech patterns and a habit of texting friends at inappropriate times. Her striking appearance features long wavy blonde hair, burgundy eyes, a beauty mark beneath her right lip, and a distinctive witch-like hat sporting bat-wing attachments and a skull motif mirroring her expressions. She wears a revealing black bustier outfit, heeled boots, shoulder-length gloves, and a collared cape fastened by a skull-adorned heart pin. Born into extreme wealth, Shiki received a monthly allowance of ¥100,000 and unrestricted access to her parents' credit cards. Her childhood shattered when her shinobi parents were killed in action, their scarred bodies returned without explanation. This trauma fueled prolonged rage and grief, causing her to lash out at peers. Kurokage discovered her weeping, adopted her, and introduced the Heart Sutra to help process her emotions. Though initially resistant, she formed a familial bond with Kurokage and his granddaughter Yumi, eventually enrolling at Gessen alongside four other orphans. In combat, Shiki wields a disc-shaped scythe larger than herself, employing flashy techniques like summoning bats and poisoning opponents, reflecting her theatrical personality. Her character development centers on reassessing moral absolutes. During the Shinovi Battle Royale against Hanzo Academy, she fixated on stealing Yagyū's eyepatch but relented upon learning its sentimental value tied to Yagyū's sister. After defeating Hebijo shinobi Imu, she questioned her own dogma upon hearing Imu fought to protect others. This culminated in her sparing the renegade Mirai to encourage her writing career, openly wondering if "evil" shinobi deserved empathy. She concluded that shinobi share core motivations regardless of alignment, contrasting Gessen's rigid "Knight Templar" ideology. In the Tokyo Yōma arc, Shiki participated in the Shinobi Masters tournament after Gessen received spa resort invitations, joining other squads battling invading yōma, though her role remained ancillary to broader team efforts. Throughout her journey, Shiki maintains intellectual depth beneath her flighty exterior: she is tech-savvy, operates a blog, and enjoys literature—traits surprising allies like Mirai. She continues reciting the Heart Sutra to honor Kurokage and soothe lingering sorrow.