In the world of Ars, humans lead a decades-long war against giant beasts that ravage the lands and feed on their resources. Those tasked with fighting them are champions called nagimori, who utilize the destructive power of kannagi: beings gifted with uncontrollable magical powers. While mourning the death of his war partner, former nagimori Jiiro crosses paths with Kuumi, a young woman who has just awakened her magical powers. After the pair form a contract to save the city from a giant beast attack, Jiiro learns that Kuumi has escaped a laboratory and is being hunted by the underlings of Mezami, the head of the research facility. Reluctantly agreeing to help Kuumi flee from her pursuers, Jiiro starts traveling with his new partner and her friend Myaa, a young girl with a cat headdress. As the unlikely trio wanders the Arsian lands, top officials begin setting their plans into motion—and the group of adventurers soon discover that men are to be feared more than monsters.

Arisugawa Academy's DJ unit Lyrical Lily is known for bringing smiles to people's faces through music. Thanks to their efforts, the local city hall requests them to perform monthly for a year as part of Operation Beckoning Cat, the town revitalization project. Unfortunately, given the long and demanding event, Lyrical Lily wonders if they can successfully meet the expectations placed on them. To better their chances, they decide to invite the DJ units that supported them during their first performance: Happy Around, Photo Maiden, Peaky P-key, Rondo, and Merm4id. Intrigued by the opportune event, the other units gladly accept Lyrical Lily's request. However, the project is extremely demanding. To attract visitors and new residents to the town, the energetic girls of the participating DJ units must give their best to create a memorable experience for their audiences.

Marina, the most beautiful mermaid in the royal Merman family, is curious about the human world. One day, she sees a handsome prince on a boat. Suddenly, a storm comes up, throwing him into the sea. Marina saves her handsome prince and guides him to the shore. Marina falls deeply in love and desperately wants to become a human. Despite the hazards, she is willing to risk it all for love.

Saenome are tasked with sealing spirits that possess objects and pose a threat to society. Known as tsukumogami, these spirits are generally non-violent, and saenome normally seal them after a simple verbal exchange. Traumatized by a previous deadly encounter with a malevolent spirit, Hyouma Kunato refuses to use peaceful methods and gets into physical confrontations with all tsukumogami that cross paths with him. Deeming this behavior unacceptable for a future clan leader, Hyouma's grandfather, Zouhei, proposes that he starts living with Botan Nagatsuki, a young woman whose family is composed of six tsukumogami—lest he be excommunicated. Determined to track down the spirit that took everything from him, Hyouma reluctantly accepts Zouhei's proposal. As unknown groups of evil spirits begin to jeopardize the balance between worlds, the young man must gain the trust of Botan and overcome his hatred for her mysterious family.