The opening twenty minutes are pure spectacle, a battle between oni and humans rendered in fluid, painterly detail that makes every other action anime look cheap by comparison. Then the actual story starts, and you're saddled with a kid who screams at everything and contributes almost nothing to the conflict around him. What keeps you watching is the film's refusal to pretend he matters, the real war between demons and humans unfolds with or without his input, and the beauty of that animation never stops carrying the weight of what's actually at stake.
A teenage boy's ordinary life shatters when he's pulled through time into Heian-era Kyoto, landing in the midst of a brutal conflict that shouldn't exist in any history book. Demons and humans wage open war in the ancient capital, and this modern kid finds himself caught between two worlds with no way home. As he struggles to survive in a time of swords and supernatural horror, he discovers that his arrival isn't coincidence. There's something about him that matters to this war, something that might change everything. The film balances visceral action sequences with moments of genuine dread, creating an atmosphere where beauty and violence coexist in a historical setting now haunted by darkness. If you're drawn to stories about ordinary people thrust into extraordinary circumstances, or if you want time travel that serves the action rather than becoming its own plot device, this delivers. The shift between familiar medieval Japan and the nightmare lurking beneath its surface gives the whole thing an unsettling edge that keeps you guessing what comes next.