"Yo-kai Watch: The Movie" centers on Nate Adams, a young boy who discovers a mysterious gachapon machine that grants him the Yo-kai Watch, a device allowing him to see and interact with Yo-kai, supernatural beings influencing human emotions and events. The narrative begins with Nate befriending Whisper, a butler-like Yo-kai, and Jibanyan, a cat-like Yo-kai, as they embark on adventures to solve everyday problems caused by mischievous Yo-kai.

The plot intensifies when a powerful and ancient Yo-kai named Dame Dedtime awakens, threatening to sever the bond between humans and Yo-kai. Dame Dedtime, once a guardian of harmony, becomes corrupted and seeks to eliminate all Yo-kai from the human world. Nate, alongside his Yo-kai companions, must uncover the truth behind Dame Dedtime's transformation and find a way to restore balance. The journey leads them to confront the origins of the Yo-kai Watch and the history of the Yo-kai world, revealing deeper connections between humans and these supernatural entities.

Key characters include Nate, whose curiosity and bravery drive the story; Whisper, who provides guidance and comic relief; and Jibanyan, whose loyalty and determination make him a standout ally. Dame Dedtime serves as the primary antagonist, embodying the consequences of broken bonds and the dangers of unchecked power. The film explores themes of friendship, responsibility, and the importance of understanding between different worlds, all while maintaining a lighthearted and adventurous tone. The narrative culminates in a climactic battle where Nate and his friends must use their wits and teamwork to overcome Dame Dedtime and preserve the coexistence of humans and Yo-kai.