The successor and branch manager of the Himeya Company—one of the many Undine associations housing female gondoliers—Aika S. Granzchesta surprises everyone when she rejects tradition and refuses to inherit the company's legendary gondola. Aika's apprentice Azusa B. McLaren, unable to wrap her mind around her mentor's unexpected decision, confronts her directly but to little effect. To better understand her reasoning, Azusa and her fellow Undines secretly plan to arrange a meeting with Aika. With the much-awaited winter days in sight, accompanied by the tranquility and sublimity of Neo-Venezia, Aika reminisces about her journey as an Undine that forged her into the person she is today. As she vividly remembers all those invaluable experiences of the past, she trusts they will continue to guide her into the unknown yet boundless future.

Chihaya Ayase, a strong-willed and tomboyish girl, grows up under the shadow of her older sister. With no dreams of her own, she is contented with her share in life till she meets Arata Wataya. The quiet transfer student in her elementary class introduces her to competitive karuta, a physically and mentally demanding card game inspired by the classic Japanese anthology of Hundred Poets. Captivated by Arata's passion for the game and inspired by the possibility of becoming the best in Japan, Chihaya quickly falls in love with the world of karuta. Along with the prodigy Arata and her haughty but hard-working friend Taichi Mashima, she joins the local Shiranami Society. The trio spends their idyllic childhood days playing together, until circumstances split them up. Now in high school, Chihaya has grown into a karuta freak. She aims to establish the Municipal Mizusawa High Competitive Karuta Club, setting her sights on the national championship at Omi Jingu. Reunited with the now indifferent Taichi, Chihaya's dream of establishing a karuta team is only one step away from becoming true: she must bring together members with a passion for the game that matches her own.

Chihaya Ayase is obsessed with developing her school's competitive karuta club, nursing daunting ambitions like winning the national team championship at the Omi Jingu and becoming the Queen, the best female karuta player in Japan—and in extension, the world. As their second year of high school rolls around, Chihaya and her fellow teammates must recruit new members, train their minds and bodies alike, and battle the formidable opponents that stand in their way to the championship title. Meanwhile, Chihaya's childhood friend, Arata Wataya, the prodigy who introduced her to karuta, rediscovers his lost love for the old card game.