Hakone is the central character of a comedy and supernatural story, where she appears as a self-proclaimed hot spring spirit and the master of the Hakone hot spring source. She is known as one of the seven hot spring spirits of the Hakone area. Her awakening occurs when a high school student named Tōya accidentally drops a steamed bun offering into the well where she is enshrined, while making a wish for good luck with his romantic interest.

Due to an exceptionally long slumber, Hakone’s powers have significantly weakened, which has the side effect of making her physical form resemble that of a young girl. Despite her childish appearance, she is a being of considerable age and status, and her primary motivation is to recover her lost power to return to her original, full adult form. She is also described as a deity of marriage and connections, or a matchmaking god, which ties directly to her role in the story of helping Tōya win the affection of his older crush, Haruna.

In the story, Hakone’s role is that of a mischievous and proactive supernatural guide. After being awakened, she begins living with Tōya and involves him in her quest to regain her strength. As part of her efforts to help Tōya with his romantic life, she frequently uses her magical yosegi puzzle box, a traditional piece of Japanese marquetry art that functions as a tool for her powers. Her role eventually expands as she is hired by the local association of hot spring owners to serve as their official ambassador.

Hakone’s key relationships are central to the plot. Her most important connection is with Tōya, the boy who awakened her and who she now helps, even as her actions often lead to chaotic situations for him. She has a notable rivalry with Miya, the spirit of the Miyanoshita Hot Springs, who is dressed in gothic attire and initially seeks to battle Hakone. However, they later join forces to face a greater threat from newer hot spring spirits. She also interacts with Haruna, the girl Tōya likes, and Haruna’s younger sister, Aki, who accompanies the group on adventures.

Regarding her development, Hakone’s journey is defined by her transition from a weakened, child-like state to gradually regaining her former power. This is a constant motivation that drives her actions throughout the narrative. Her personality is playful and powerful, often leading her to take charge of situations, but her small stature and supernatural origins are a constant source of comedic interaction with the human characters around her. Her most notable abilities include the power to influence romantic fortune, which she uses in her role as a matchmaking deity, and the supernatural control over her yosegi puzzle box. When her powers are fully replenished, she is capable of transforming from her child-like form into her true, mature adult body.