Hana Yurikawa is a central character and the best friend of the protagonist, Miko Yotsuya. As a high school student, Hana is an energetic and sociable girl known for her cheerful and bright personality. She has a very strong appreciation for cute and sweet things and is often portrayed as being a bit air-headed or innocent. One of her most defining characteristics is her enormous appetite; she is a glutton who is constantly hungry and is famous for never skipping what she calls her after-breakfast meal. Her need to eat constantly is not merely a personality quirk but is directly tied to her unique spiritual nature.

Hana's primary role in the story is to serve as Miko's pillar of emotional support, providing her with a sense of normalcy and friendship amidst the terrifying supernatural events Miko endures. She is completely unaware of the ghosts and spirits that surround her, as she has no ability to perceive the supernatural world. Ironically, despite her fear of scary things and bugs, Hana possesses an exceptionally powerful life aura, described by those who can see such things as a massive, roaring white flame that completely eclipses her body. This aura is so potent that it can automatically incinerate or repel weaker, lesser spirits simply by being near them. However, this powerful defense comes with a significant drawback. The aura consumes a vast amount of her internal energy, which is why she must eat constantly to replenish it. The energy from the food she consumes is absorbed by her aura, which explains why she never gains weight from her massive diet. This unique condition also attracts more powerful and malevolent entities that seek to feed on her abundant life force, creating a different kind of danger for her and those around her.

Key relationships shape her interactions throughout the story. Her bond with Miko Yotsuya is the most significant. Hana deeply trusts Miko and is an important part of her life, even while being completely oblivious to the daily horrors Miko faces to protect her. Her kindness and compassionate nature are also extended to others, such as when she forgives a classmate who was actively trying to harm her, redeeming that person through her warmth. She also helps to bring another friend, Yuria Niguredou, into their social circle, undeterred by Yuria's prickly exterior. Hana's development is closely tied to her spiritual condition. When her powerful aura begins to run low, she becomes sickly, weak, and lethargic, which creates a point of vulnerability and concern for her friends. Her primary motivation is to continue living a peaceful and happy life alongside her friends, a simple goal that is constantly put at risk by the supernatural forces drawn to her and the struggles Miko hides from her. Her notable ability is her passive but immensely powerful life aura, an unconscious defense mechanism that shapes both her own needs and the story's conflicts.