Sumire Hanano, a first-year Mizusawa High student, joins the karuta club to pursue Taichi Mashima, the club president, driven by romantic ambition rather than interest in the game. Fresh from a breakup with Kazuki, who ended their relationship via text, she redirects her affections toward Taichi, masking emotional vulnerability with calculated charm. Obsessed with her image, she dubs herself the "Mascara Shogun," though she begrudgingly acknowledges Kanade Oe’s superior eyelashes as a subtle threat to her self-styled title.

Sumire’s chest-length black hair falls in low twin pigtails, framed by square bangs and golden-brown eyes. Her 158 cm stature is accentuated by a school uniform accessorized with a plaid ribbon and a yellow jacket bearing the school crest. Without makeup, her features adopt a simpler, less striking appearance.

Initially dismissive of karuta and the Hyakunin Isshu poetry, her vanity gradually gives way to responsibility as Kanade persuades her to stay in the club. She joins the Shiranami Society’s C Class, immerses herself in tournament strategizing, and gathers intel to support teammates—a stark shift from her earlier indifference. Her romantic fixation on Taichi persists, fueling rivalry with Chihaya Ayase, whom she views as a competitor for his attention. Yet loyalty to the club endures even after Taichi departs temporarily for academic reasons. By her second year, she mentors new recruits, embodying the role of a dependable upperclassman.

Interactions with teammates like Akihiro Tsukuba reveal her unspoken attachment to karuta, contradicting her initial denials. Pragmatic and socially astute, she leverages chocolate-making skills to navigate group dynamics. Her narrative arc traces a duality of self-deception and growth: karuta transforms from a tool for romance into a genuine passion, even as her pursuit of Taichi lingers. This tension underscores her journey—a balance between lingering superficiality and emergent maturity, woven into the club’s collective ambition.