Manami Kuroha is the ghost apprentice of the magician dispatch company Astral. She has no memories of her life before her death except for her own name. She originally haunted a hospital, unable to interact with the living, until she was discovered and recruited by Itsuki Iba, the second president of Astral, who offered her a place within the organization. As a member of Astral, she takes on the role of an intern and is highly capable of managing the company's schedule. Her personality is described as captivating and diligent, and she studies hard with a strong desire to become a useful part of the team. Despite her spectral nature, she is cheerful and earnest in her duties, which initially involve cleaning the office and serving tea, tasks she could not perform until she developed her supernatural abilities.

Over the course of the story, Kuroha undergoes significant personal development. She begins with no ability to affect the physical world at all, but gradually learns to use poltergeist and apport abilities, which allow her to move objects and manifest physical matter from her own ethereal body. She practices these skills while performing her ordinary chores, and her power grows to the point where she becomes a capable defender, second only to Mikan Katsuragi among Astral's members. She also has the ability to channel power through the Sefirot to manipulate reality, though she does so in unorthodox ways since she is not a trained Kabbalist. She is adept at protection and movement effects, and as a ghost herself, she can see and interact with other spirits.

Kuroha can change her outward appearance at will, and she frequently chooses to appear in a maid outfit, especially after episode sixteen of the anime. She is often seen carrying a tea service tray that appears to float on its own, using her powers. Her relationship with Itsuki Iba is central; she initially joins Astral after he saves her from being consumed by a Soul-Eater, and she later falls in love with him. She also works closely with the other members of Astral, such as Mikan Katsuragi, and her presence brings a gentle, supportive dynamic to the group. Her motivations stem from a desire to belong and to contribute meaningfully to Astral, and she takes pride in her organizational skills and her ability to support the team in both mundane and combat situations. Her development from a powerless ghost into a valued and capable member of Astral is a key part of her story arc.