Youkai Watch Movie 4: Shadow Side - Oni-ou no Fukkatsu

Thirty years after the Youkai Watch once connected Keita Amano to the spirit world, the watch has faded into legend and most humans can no longer see Youkai. That fragile separation begins to collapse when Onimaro begins spreading through the city, feeding on people's malice and transforming its victims into violent Kaodeka Oni.

A new generation is drawn into the crisis: Natsume Amano, Touma Tsukinami, and Akinori Arihoshi each become tied to the supernatural in different ways. With a new Youkai Watch, spirits capable of shifting between Lightside and Shadowside forms, and the return of an ancient threat known as the Oni King, they must confront a disaster that endangers both the human and Youkai worlds.