Ebisu is a young magic user and a member of En's family organization, where she serves as the unofficial partner to Fujita. She is a girl of small stature, appearing somewhat androgynous, with short purple hair and violet eyes. Her typical attire consists of a black turtleneck, purple leggings adorned with arrow-shaped metal plates, and black combat boots. She carries two small scythes on her back and is never seen without her signature skull mask, the design of which varies throughout the story.

Before suffering a severe trauma, Ebisu was a quiet, sophisticated, and rather apathetic child who came from a wealthy family. Her parents believed her to be a normal, cute girl with great expectations for her future, unaware of her secret use of black powder, which she kept hidden in her bedroom. For reasons unknown, she eventually left home to live on her own, becoming a successful and well-known smoke dealer. Her magic, a reptile transformation type, was highly sought after because its effects were enhanced by her early and frequent consumption of black powder.

Ebisu's life and personality are drastically altered following an encounter with Kaiman and Nikaido in the Hole. During a practice trip, Kaiman bit down on her head. As Fujita pulled her free to save her, her face was torn off, causing immense physical and emotional trauma. Though Noi healed her physical wounds, the psychological damage left her unable to articulate her thoughts properly, leading to silly and pronounced speech. Her personality transformed completely into that of a deviant, hyperactive, and seemingly nonsensical brat who often annoys others to get what she wants. This trauma also resulted in amnesia, causing her to forget most of her past life.

Following this incident, Ebisu stays at En's mansion, with the family treating her as a member despite her erratic behavior. Her primary role within the group is to accompany Fujita on errands and missions, though her actions are often chaotic and unpredictable. She accompanies the team on several key missions to the Hole, including an attempt to kill Kaiman and Nikaido during the Night of the Living Dead, where she is turned into a zombie before being healed. In a notable incident, she consumes an energy drink laced with a smoke enhancer, causing her to morph into a giant, rampaging reptile creature. On another occasion, she tails En through the city, annoying him until he throws a ball of money to get rid of her.

Ebisu is indirectly responsible for Kaiman's lizard head, as her unstable magic is the origin of his transformation. Her magic is a reptile transformation type with mutagenic effects that turn people into wild, violent lizard-like creatures. Due to her childhood dependency on black powder, her smoke has severe side effects. Victims of her magic become uncontrollable and go on violent rampages, attacking anyone in sight, and they also suffer from severe amnesia. While her power is volatile and unpredictable, En notes that it could be useful if she learns to control it. Ebisu herself is an exception to the feral side effects, largely retaining her faculties when she transforms.

Her closest relationship is with Fujita. He is the one who saved her from Kaiman, and she becomes his unofficial partner, replacing the deceased Matsumura. Despite the chaos she causes, she shows a unique regard for him. When Fujita is despondent and no one else applies to be his partner during the Blue Night, Ebisu is the sole applicant, presenting the form to him with a blush. After she is killed in a fight and later resurrected, a "Positivism" hair clip is left lodged in her brain. This, combined with the trauma of her death, cements her return to her silly, erratic personality, even after she briefly recovered her past memories and original demeanor. She also forms a close bond with Kikurage, En's small magical creature, becoming its primary caretaker and friend.