Best friends Yuu, Haru, and Kotona enjoy a tranquil high school life together. One day, however, a suspicious man pursues and stabs Kotona—a catastrophe that Yuu and Haru fail to prevent. While hastily carrying the girl to the hospital, the two boys are nearly hit by a truck but miraculously remain unharmed. Instead, they find themselves in a fairy-tale-like kingdom with an exotic diversity of people and wonderful creatures.

To their surprise, the boys discover that Yuu, who has been confined to a wheelchair since childhood, can now walk! Yet they have no time to ponder the puzzling situation, as their friend is gone. Setting off to find Kotona, Yuu and Haru stop at a local pub to inquire about her. But upon inspecting a picture of Asha, the kingdom's princess, the two have a shocking revelation.

Narrating an extraordinary adventure in a magical world, Ni no Kuni demonstrates the special connection between two separate yet parallel worlds and its manifestation of the bonds between individuals.

Released in Japan on August 23, 2019 and on Netflix worldwide on January 16, 2020, Ni no Kuni is an anime adaptation of the acclaimed video game series of the same name. Studio Ghibli contributed character designs and other components to the games, but it is notably not associated with the movie, despite its similar visual tones and textures.

Ni no Kuni was the first feature-length work directed by Studio Ghibli's animator Yoshiyuki Momose, who has served as the director of animation in addition to having drawn character designs and storyboards for the games. Moreover, the film features a score from Studio Ghibli's collaborator and composer Joe Hisaishi, who has also acted as the lead composer for the games' music.

While the film's narrative differs from the plot in the games, the movie's story includes elements from the games such as the setting, racial diversity among the characters, names, and visual references to particular individuals and items.