Legend has it that when you eat the flesh of a mermaid, you would live forever. Yuta and Mana are living proof of this... Together, they journey to various places trying to find meaning for their existence, or perhaps even a "cure" for their situation. One day, Yuta and Mana meet Masato, a little boy who seems terrified of his mother Misa. It seems to Yuta and Mana that mother and son have a very unusual relationship. What happens when Yuta and Mana decide to discover the dark secret Masato and Misa are hiding? And what about those monster-like creatures that have been appearing?

Akanemaru, a skilled sculptor, sets out to find the muse for his masterpiece, the legendary immortal bird Phoenix. However, on his journey, he encounters unexpected trouble when he runs into Gaou, a one-eyed, one-armed bandit. Despite Akanemaru's friendly demeanor, Gaou, who harbors animosity toward the world as a ruthless man, attacks and robs him. As they go their separate ways, the unfortunate incident fades into oblivion. Years later, Akanemaru is forced to accept a new assignment and abandon his dream, while Gaou is stricken with sudden misfortune—a twist of fate that will change both their lives forever. But little do they know that these new circumstances will eventually lead them to cross paths once more: this time as rivals. Set in Japan's Nara period, Hi no Tori: Houou-hen explores the fragile balance between action and consequence as it follows the lives of two men who must inevitably confront the responsibilities of their choices.

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.