Sixteen-year-old Ohana Matsumae lives in Tokyo with her single mother, Satsuki Matsumae, until Satsuki abruptly elopes with her boyfriend to escape his debts. This abandonment forces Ohana to relocate to the countryside and live with her estranged grandmother, Sui Shijima, proprietor of the historic hot spring inn Kissuisō. The move occurs shortly after Ohana's childhood friend, Kōichi Tanemura, confesses his feelings to her—an event left unresolved when he departs before she can respond, creating lingering awkwardness.

Raised under Satsuki's philosophy of "rely only on yourself," Ohana developed strong self-reliance from a young age, becoming proficient in cooking and household management due to her mother's neglect and inconsistent parenting. This instilled a pragmatic yet optimistic outlook but also led to tendencies of acting independently without considering others. Upon arriving at Kissuisō, Sui puts Ohana to work at the inn to compensate for her stay, thrusting her into an unfamiliar environment where her ideals clash with established routines and staff dynamics.

Her initial experiences highlight struggles: facing hostility from apprentice chef Minko Tsurugi, who nicknames her "Hobiron" and frequently tells her to "die"; navigating the shyness of part-time waitress Nako Oshimizu; and enduring Sui's stern discipline, including physical reprimands. Despite this, Ohana's innate sense of justice and desire to help drive her efforts to improve situations, though her impulsive actions often backfire, like forcibly confronting Minko and Nako or mishandling tasks. Her persistence and genuine intentions gradually earn the staff's respect, forging friendships and integration.

Ohana's development centers on evolving self-awareness and relationships. She transitions from stubborn self-reliance to understanding the value of collaboration and trusting others to overcome difficulties. This growth reflects in her reconciliation with Koichi, realizing her feelings for him; they resolve misunderstandings and establish mutual romantic connection. Simultaneously, her fraught relationship with Satsuki—mirroring Satsuki's own estrangement from Sui—begins to heal as Ohana learns about her mother's past through Denroku Sukegawa's journals discovered during events at Kissuisō. These logs reveal Satsuki's teenage rebellion there, her encounter with Ohana's father (a photographer who inspired Satsuki's career), and her subsequent efforts to be a better mother despite flaws. This knowledge fosters Ohana's empathy, forgiveness, and nuanced appreciation of their bond.

Her personality combines energetic optimism with occasional naivete, leading to humorous or dramatic misunderstandings. She is quick-witted, outspoken, and prone to misinterpreting social cues—traits that inadvertently attract junior chef Tohru Miyagishi, though she remains oblivious while supporting Minko's feelings for him. Ohana exhibits resilience during crises, like spearheading efforts to save Kissuisō from closure. Quirks include sensitivity to alcohol (becoming tipsy from soda), frequent nosebleeds, and preferring cola mixed 50-50 with black tea to reduce carbonation.

Physically petite with short, frizzy light-brown hair and bright-brown eyes, Ohana strongly resembles her mother. Her name, chosen by her father, carries dual meanings: in Japanese, "thread" (緒) and "flower" (花), reflecting a delicate yet blossoming identity; in Hawaiian, "Ohana" means "family," symbolizing her journey toward redefining kinship and belonging at Kissuisō.