OVA
Description
Celty Sturluson is a Dullahan, an Irish folklore being who guides souls to the afterlife. Originating from Ireland, she journeyed to Japan centuries ago after the scientist Shingen Kishitani stole her head using the ancient sword Saika, splitting her soul. This loss created significant memory gaps, leaving only fragmented recollections of her past existence, including violent acts like splashing blood on humans who called her a monster.

Upon arriving in Japan, Celty agreed to let Shingen perform a full autopsy in exchange for his silence, an experience that traumatized her due to remaining conscious. She eventually formed a life with Shingen's son, Shinra Kishitani, who had been fascinated by her since childhood. They developed a romantic relationship, with Celty gradually reciprocating Shinra's feelings despite initial reluctance. She worries Shinra's attraction might be to Dullahans in general rather than her specifically and fears another of her kind could disrupt their relationship.

Celty perceives her surroundings through shadow-like particles acting as sensory organs, detecting light, vibrations, and scents. Her vision originates from where her head would be but can extend to any part of her body, offering a slightly wider field than humans. Without biological needs like blood circulation or sweat production, her physical strength exceeds humans but remains below individuals like Shizuo Heiwajima. She feels pain but heals rapidly and is nearly indestructible. Her primary ability involves manipulating a durable, weightless shadow substance to form clothing, armor, weapons like her signature scythe, and other objects. This shadow matter appears as two-dimensional silhouettes in lore but adapts visually in animated media.

She works as an underground courier in Ikebukuro, operating anonymously as the "Black Rider" or "Headless Rider." Her motorcycle, Shooter, is a shapeshifting Cóiste Bodhar. To conceal her identity, she wears a feline-inspired helmet and communicates via text on a PDA or through projected emotions when necessary.

Initially detached and wary of humans due to negative reactions to her appearance, Celty developed a more relatable personality over time. She exhibits dry humor, optimism, and kindness, such as rescuing suicidal individuals like Rio Kamichika and Mikado Ryuugamine. However, she harbors insecurities about her monstrous nature and fears abandonment. She enjoys human activities like online chatting, television, and gaming but has an intense phobia of aliens. Celty values her job intensely, rarely taking days off, which strains her time with Shinra.

Her quest for her head drives much of her narrative. Early encounters include chasing a girl resembling her (Mika Harima) and confiding in Mikado about her true nature. She later learns Shinra knew her head's location but concealed it to protect their life together. This causes conflict, though Celty insists she would stay with him even with restored memories. She eventually shifts focus toward preserving her current life, accepting that her past self might be fundamentally different.

Celty integrates into Ikebukuro's social fabric, joining the anonymous gang Dollars and later Snake Hands. She forges bonds with humans accepting of the supernatural, such as Shizuo, Anri Sonohara, and Mikado. Her relationships highlight her belief that everyone harbors secrets, rejecting the idea of "normal" people. She intervenes in city conflicts, including the three-way standoff involving the Dollars, Yellow Scarves, and Saika-wielders, often countering manipulations by figures like Izaya Orihara.