Ext. Mountain inn, hot spring — Night
Prologue Japan, 1890
Japan, 1890. Outside an ornate mountain inn, a man sheds his kimono, revealing a torso covered in traditional Edo-period tattoos. He eases into a steaming, moonlit pool. A monstrous entity emerges from the trees wielding a scythe. It drags him under, slits his throat and peels the tattooed skin from his back in a single sheet. The water turns blood red.
Int. London hotel, front desk — Day
Act One Present day
London, present day. Ken (mid-20s), a half-Japanese British hospitality graduate, is the most overqualified man on the front desk of a mid-range London hotel, serving guests who barely acknowledge him and pitching ideas to a boss who wishes he wouldn’t. Under his crisp shirts, his back is covered in tattoos. At home, a solicitor’s letter reveals that his estranged father has died, leaving him a rural Japanese hot-springs hotel. His ailing mother persuades him to investigate: finally, a chance to put his degree to use, sell the place and give them both a better life.
A bewildering journey to a remote, forested valley in Nagano, Japan ends at a crumbling onsen hotel with no guests and staff who want nothing to do with him. Practical, sharp-tongued Rina (early 30s) claims not to speak English; Toshi (70s), the weathered, usually half-cut groundskeeper, answers his request for Wi-Fi with a booming laugh. Exploring the hotel and its sprawling grounds, Ken discovers unusual artefacts, crates of dynamite, a photograph of his parents together and ledgers revealing serious debts. He also finds the estate’s abandoned saltworks and an uphill reservoir fed by a saline spring, separate from the hotel’s bathing supply.
Ext. The hot springs — Night
Act Two
Ken throws himself into repairs, finding an unlikely father figure in Toshi. He gets the internet working and lists the onsen on Airbnb. His sole guest is Ricky Parvis (early 40s), a tactless, overly enthusiastic American anime obsessive, insufferable and delighted by everything, who irritates Rina enough to snap into English. She admits she is Ken’s half-sister, furious that the hotel she kept afloat was left to the son who never visited. News of the reopening brings local yakuza boss Masato Kuroda and his men to collect a personal, off-the-books loan he made to Ken’s father. Ken calls the police, only to discover they’re on the gangsters’ payroll. Kuroda’s men trash the hotel and beat Ken at the forest’s edge, spilling his blood onto the soil.
Desperate to make the hotel profitable, Ken ignores Toshi and Rina’s warnings and reopens the hot springs, removing old boundary markers he mistakes for obstructions. That night, Kawahagi, the ancient Skin-Taker, lures him into the water and cuts a strip of tattooed skin from his back. A drunken Toshi drives it back with brine from the saltworks reservoir, but the wound leaves Ken able to perceive the Yōkai: bizarre, terrifying spirits inhabiting the hotel and surrounding forest.
As Rina tends his injuries, she begins to accept that their father abandoned Ken too. Their hostility gives way to an uneasy bond. Kuroda and his gang take over the hotel, threaten Rina, and attack Toshi when he intervenes. Kuroda has the place under control until his men use the springs, where harmless-looking forest creatures turn into vicious Yōkai and butcher several of them.
A debt owed in skin
Toshi buries the bodies and finally explains what Ken has inherited: a debt owed in skin. In 1890, Ken’s ancestor diverted a sacred healing stream to supply the hotel, starving the forest and draining the water of its power. The family has profited ever since, while generations of yakuza have compounded the desecration by burying murdered rivals among the trees. Protective boundaries kept the spirits at bay until Ken’s renovations and the gang’s latest violence breached them. Kawahagi treats tattooed flesh in sacred water as a desecration and collects it as payment, but the debt keeps growing while the theft continues.
Ken learns the hotel sits on the route of the Night Parade of a Hundred Demons, which passes once a century. Ken has sullied the water in its path, and it is already coming up the mountain. Rina traces the stream’s original course on an old estate plan and identifies a sluice that could restore it, but the Parade has already cut off access.
By nightfall, grotesque spirits swarm the woods and the buried gangsters claw their way out of the earth. More of Kuroda’s men arrive looking for them, supplying the Yōkai with fresh fodder. An imperious old man has settled in the hotel’s tea room as though he owns it. Ricky recognises Nurarihyon, the Parade’s leader, and tells Ken that Kawahagi answers to him. A creature disguised as Toshi slips inside. The real Toshi fights it in blessed armour but is fatally wounded.
Int. Hotel kitchen — Night
Act Three
Trapped between armed gangsters and an onslaught of Yōkai as the Night Parade marches through the hotel, Ken and Rina barricade themselves in the kitchen with Toshi’s body. Ken dons Toshi’s armour to hold off the spirits, but they conclude only a flood of brine from the old saltworks reservoir can break the siege. Ricky volunteers. He carries the construction dynamite up the mountain and delivers a speech he has clearly been drafting since he arrived, in appalling Japanese, to an audience of monsters. The monsters attack, cutting off his escape. He detonates the charges, destroying the reservoir’s retaining wall and sacrificing himself.
The brine rushes down an old channel across the Parade’s route, scattering the spirits and breaking the siege. Kuroda abandons his men to retrieve cash and valuables from his car. The flood catches him in the lower grounds and kills him, while his remaining enforcers perish in the onslaught of Yōkai.
Nurarihyon remains inside the hotel, calmly taking tea. Ken reaches him and, with Rina translating, offers to restore the forest’s water. Nurarihyon demands a final payment for the generations of exploitation. Ken offers his tattooed skin in return for releasing Rina and every future descendant from the debt. Nurarihyon accepts, allowing the hotel to coexist with the forest once the stream is restored and the offering made.
Ken faces Kawahagi in a forest pool on the stream’s original course, recognising the stolen strip of his tattoo among the skins it wears. He removes the armour and kneels willingly. Kawahagi peels the tattooed skin from his back in a single sheet. As Ken sinks, Rina opens the old sluice, sending the restored stream into the pool. The sacred water closes his wounds, leaving his back scarred and bare of tattoos. Ken surfaces, alive. Kawahagi lays the ancestor’s skin beside Ken’s in the current and leaves with the Parade.
Ext. The hotel — Day — Months later
Epilogue
Months later, the siblings rebuild the hotel as joint owners, welcome Ken’s mother to Japan and reopen under a name honouring Ricky.
Fortunately, amid all his disastrous business decisions, Ken remembered to take out insurance.
