Movie
Description
Stone River, alias Sōseki Ishinagare, serves as a core operative within the Phantom Thief Empire's elite Three Cards, answering directly to their leader, Lady Arsene. He maintains a double life operating undercover at Holmes Detective Academy as its head chef and groundskeeper, using the name Sōseki Ishinagare. Visibly, he stands 176 cm tall and weighs 63 kg, with distinct violet hair styled in a short ponytail featuring a curtained middle part, complemented by amber eyes. His practical attire typically consists of a changshan, trousers, a turtleneck tank top, and a wristband, often accompanied by a katana.

His primary "Toy" ability is dollification, allowing him to immobilize opponents into statue-like dolls through eye contact. Victims usually regain mobility after a period, though the power carries risk, as evidenced when he accidentally froze himself upon seeing his reflection in a plate. Beyond this power, Stone River is a highly proficient swordsman and excels in essential domestic tasks including cooking, cleaning, laundry, and gardening, making him indispensable at the academy.

Initially characterized by cold efficiency and ruthless dedication to Lady Arsene's objectives, his undercover role gradually fosters a genuine, albeit conflicted, care for Holmes Detective Academy and its students. Despite this attachment, his loyalty to the Phantom Thief Empire remains absolute; he prioritizes his duties as a thief above all else and is prepared to sacrifice his life for Lady Arsene.

Within the Empire, he coordinates closely with fellow members Twenty and Rat, executing combo techniques like "Choukyuu Haou Den'eidan" and "Sekiha Love Love Tenkyoken" alongside Twenty. His interactions with Milky Holmes are adversarial, with a notable incident involving the destruction of the girls' garden triggering intense mutual animosity and retaliation.

He participates in the conflict depicted in *Gekijōban Tantei Opera Milky Holmes: Gyakushū no Milky Holmes*, a three-way battle between the Phantom Thief Empire, Milky Holmes, and Genius 4. The confrontation escalates when the Empire attempts to steal a treasure during a Milky Holmes study tour, prompting all factions to deploy their Toys. Across his appearances, his character arc consistently explores the tension between his identity as a dedicated phantom thief and his undercover life, highlighting the internal conflict between duty and burgeoning empathy.