Call of the Night follows insomniac middle-schooler Kou Yamori, who wanders the city at night searching for meaning beyond his monotonous life. His world shifts when he meets Nazuna Nanakusa, a mysterious and carefree vampire who introduces him to the allure of the nightlife. Fascinated by her freedom, Kou decides he wants to become a vampire too, only to discover that he must first fall genuinely in love with her. As they roam through neon-lit streets, encounter other supernatural beings, and question their own emotions, Kou begins to explore loneliness, connection, and what it truly means to be alive under the moonlit sky.