Tsuzura Hanatemari, a student from an affluent family, initially attended public schools where her status made her popular. This popularity fueled jealousy in her childhood acquaintance, Mary Saotome, especially after Tsuzura's parents encouraged expensive gifts at her birthday party. Upon transferring to Hyakkaou Private Academy, Tsuzura's lack of confidence and perceived mediocre gambling skills led to quick relegation as a "housepet," a subservient role due to debt. She believed she would inevitably return to this status even if she paid her debts. Her fortunes shifted when Mary Saotome arrived at the academy. After Mary won a rematch with Tsuzura's financial assistance, the two formed a close partnership. Tsuzura began referring to Mary as "her prince," implying deep admiration and possibly romantic feelings. Characterized by kindness, politeness, and innate generosity—shown when she lent money to Mary without hesitation—her time as a housepet also left her timid and shy. She displayed naivety, misunderstanding the implications of "spending the night together" during a school event until corrected. Through Mary's influence and their collaboration managing a gambling den with Yukimi Togakushi, Tsuzura gradually gained confidence in her gambling abilities. Key events tested her loyalty: during the "Coupling Party," Mary suspected betrayal and temporarily excluded her. Tsuzura continued trusting Mary, participating in the gamble without knowing the group's strategy. After Mary apologized for her distrust, Tsuzura tearfully hugged her, expressing relief at not being abandoned. Later, during a treasure hunt, she assisted Mary by solving riddles and swapping a real chest for a fake one. Her skills evolved further when she defeated Eneru Rokujou in a photography gamble by drawing confidence from how Mary would approach the situation. Outside gambling, she enjoys domestic activities like cooking and sewing, embodying the "Yamato Nadeshiko" ideal. Tsuzura eventually left the academy to study piano abroad. Before departing, she gave Mary her flower hairpin as a keepsake; Mary later clutched this hairpin while reflecting on the housepet system, indicating Tsuzura's lasting impact. While the anime adaptation briefly hinted at a tragic fate, the source material clarifies her departure was for educational purposes.