Botan serves as a guide to the Spirit World, a role functionally equivalent to a grim reaper, though her appearance and demeanor defy the grim associations of that title. Her name means peony in Japanese. She is a spirit charged with ferrying the souls of the deceased to the Spirit World to face their final judgment. Unlike the Western concept of a singular, cloaked figure with a scythe, Botan is one of many such guides and is depicted as a young woman with long blue hair typically tied in a ponytail, pink eyes, and a cheerful expression. Her standard attire while on duty is a light-pink kimono with a white obi sash, though she often adopts casual human clothing or disguises herself, such as in a school uniform or in formal wear when acting as a trainer.

Botan's personality is a study in contrasts to her somber profession. She is genuinely helpful and well-meaning, with a bubbly, talkative, and cautiously optimistic nature. She can be somewhat clumsy, short-sighted, and is occasionally a bit of a scaredy-cat, despite her responsibilities. Her initial interest in the main character, Yusuke Urameshi, was more clinical, viewing him as an interesting subject. However, through her close involvement in his affairs, she develops a strong personal bond with him and becomes one of his most valuable and loyal allies and close friends. Her primary motivation is to fulfill her duties to the Spirit World and its ruler, Koenma, but she is driven by a genuine care for the well-being of Yusuke and the human world. She is not motivated by romantic interests, as she does not enter a romantic relationship with any character throughout the series.

In the story, Botan acts as the primary liaison between the Spirit World and the living world. She is first introduced to inform Yusuke of his death and to oversee the trials required for his resurrection. After Yusuke is revived and appointed as the Spirit World's detective, she becomes his assistant and guide. In this capacity, she provides him with crucial information about new cases, teaches him how to use various detective tools like the Concentration Ring and Communication Mirror, and delivers messages from Koenma. She often accompanies Yusuke and his allies into the field, providing support. During the Maze Castle incident, she works to combat a plague of mind-controlling Makai insects and protects Yusuke's friend, Keiko. In the Dark Tournament arc, she serves as the team's coach and provides moral support, and it is she who must perform the grim duty of guiding the soul of their mentor, Genkai, to the Spirit World after her death. Throughout the Chapter Black and Three Kings sagas, she continues to assist the team by gathering intelligence, helping to rescue kidnapped allies, and offering support.

Her key relationships center on the main cast. Her closest and most significant bond is with Yusuke Urameshi, whom she evolves from observing to genuinely caring for as a friend. She also works closely with Kazuma Kuwabara, who initially develops a fleeting crush on her. She is a trusted subordinate of Koenma, the young ruler of Spirit World, and she forms a strong, protective bond with Yusuke's human friends, especially Keiko Yukimura, whom she risks her life to save. Her relationship with the more reticent members of the team, Hiei and Kurama, is that of a reliable, if sometimes overly chatty, colleague.

Botan exhibits a subtle but clear development over the course of the series. Initially portrayed as a somewhat naive and by-the-book guide, her extensive time with Yusuke and his friends exposes her to the messiness and emotional weight of mortal life. Her attachment to them deepens to the point where she is profoundly affected by their losses. The death of Genkai is a pivotal moment for her, as it forces her to confront the grief that accompanies her duty, shifting her from a detached observer to someone who personally fears losing the people she cares about. This experience tempers her trademark optimism with a more mature understanding of loss and sacrifice.

Her notable abilities are unique to her station. She is capable of flight by manifesting and riding on a wooden oar, which she can also use as a bludgeoning weapon. She has displayed mild spiritual healing powers, most notably used to slow and partially reverse the demonification of Keiko after she is cut by a cursed sword. Botan possesses a degree of telepathy, able to read surface thoughts and send simple mental messages. As a spiritual being, she has heightened spiritual awareness, allowing her to sense the energies of others and determine when someone has died. She can also shift between her visible, physical form in the human world and her spiritual form. She is sometimes seen using unconventional weapons like a baseball bat or bug spray against demonic threats.