Sumireko Ogawa is a busty bookstore clerk who wants to become a novelist after some writing success in her youth. When strange occurrences start cropping up around the city, she teams up with her flirtatious co-worker Ren Adashino to look into them. But Ren is hiding a secret of his own! With their combined skills of occult knowledge, what will they discover as they investigate?

Hoping for a fresh start, househusband Masaki Fujiyoshi, his spouse Hiromu, and their toddler son, Hikari, move to a new neighborhood. The couple's union was frowned upon by many due to Masaki's status as an omega—a secondary gender that allows an individual to give birth. Even for an alpha—seen as the superior secondary gender—such as Hiromu, discrimination seems to be commonplace and a hindrance to a life of domestic bliss. Fortunately, the new family is not alone. Little Hikari becomes attached to Yuuki Hirai, the Fujiyoshis' lonely college student neighbor. Despite his initial reluctance, Yuuki ends up befriending the infant. Moreover, the family can also confide in Hiromu's childhood friend and coworker Tomohiro "Matsu" Matsuo. Although everything is going well for the young couple and their child, a sudden presence from the past might pose a problem for the peaceful life they dream of.

Since childhood, Elaina has always been fascinated by the stories written within her favorite book, especially those about Nike, a renowned witch who had numerous great travels across the world. Wanting to experience the awe of adventure herself, Elaina strives to become a witch, and despite the numerous trials that come her way, she eventually succeeds. Now a full-fledged witch, Elaina finally embarks on her long-awaited journey, in which she meets many people along the way, learning their various stories. Through all of this, she explores the world at its fullest—experiencing both its bright and dark sides—starting her legendary tale. [Written by MAL Rewrite]

During his summer vacation, middle school student Nagasumi Michishio travels to the Seto Inland Sea. One day, while swimming at Mio Sun Beach, his leg suddenly cramps. No one is close enough to notice his desperate screams for help, and so he sinks into the ocean, where he is left to drown alone. Just as he loses consciousness, however, a mermaid appears and saves his life. That night, Nagasumi is visited by his savior, a girl who introduces herself as Sun Seto—a mermaid from a yakuza family. As it turns out, under mermaid law, a mermaid whose identity is revealed to a human must be punished by execution. To avoid this harrowing outcome, the Seto family propose a solution: Nagasumi must marry Sun or die at the hands of Gouzaburou, Sun's father and boss of the Seto clan. Faced with no other option, Nagasumi takes her hand in marriage. Now, the newlyweds face the difficult task of keeping their relationship secret. Between Gouzaburou's unending attempts on Nagasumi's life and the eccentric antics of a slew of antagonists, a genuine and innocent love blossoms between the pair as they adapt to their new life. [Written by MAL Rewrite]