The film's plot tells the story of how Satoshi and Pikachu came to know each other. Pikachu was not cooperative toward Satoshi, but Satoshi only wanted to be friends with Pikachu. On the day they set out from Masara Town, both of them saw a Ho-Oh flying and made a vow to someday go and meet it.

(Source: ANN, edited)

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]

Revered as heroes for their role in defending Tristain, Louise Françoise and her familiar Saito Hiraga face heavy pressure to continue protecting the Kingdom. With an uneasy peace now established within Albion, the newly crowned Queen Henrietta must deal with a political struggle brewing on the horizon. To make matters worse, a new villain has begun plotting in the shadows against the Crown. With the continuing threats that face the Kingdom, Louise and Saito are compelled to work together once more. No longer "Louise the Zero," the young mage's newfound aptitude for Void magic gives her enough power to wipe out an entire village; however, wielding these abilities comes with its share of challenges. As more conflicts arise, the idea of placing honor above oneself is put into question—regardless of their answer, their only choice is to see it through until the end. [Written by MAL Rewrite]

Second season of .