Fairy tales usually move from humdrum reality to fantasy and back again, with the protagonist and the rest of the audience transformed along the way. Think Alice and the rabbit hole, Chihiro and the tunnel in “Spirited Away.” But the CG-animated limited series “Oni: Thunder God’s Tale” opens in a Japanese dream world before crossing the threshold into an urban Japan that is darker and far more dangerous.

“Oni” is the latest work from indie animation studio Tonko House, with a script by veteran anime writer Mari Okada (“Macquia: When the Promised Flower Blooms”). The series uses digital techniques to mimic the tactile, slightly jerky movements of stop-motion animation, which makes its visuals feel intimate despite the story’s dizzying array of characters and Hollywood action-adventure scope: a four-episode, 154-minute epic that blends traditional Japanese folklore with a modern take on racial and ethnic conflict.

We land in a forest village whose quirky locals are plucked from Japan’s mythological past: gods, demons and shape-shifting yōkai spirits, including a talking one-eyed umbrella (kasa-obake), tumbling daruma dolls and a frog-like child kappa, whose head, true to historical form, bears a shallow pool of water. Each time the kappa politely bows, usually mid-sentence, water spills out and he loses consciousness until someone refills it so he can finish speaking.