This is one room where guests should probably knock on the door before entering.

Back again for its fourth run from its initial debut in 2015, Universal Studios Japan's official hotel, Hotel Universal Port, has Halloween-themed hotel rooms filled with all sorts of scary surprises to spook guests.

Horror-themed hotel room

This year's theme is Switches, where your room turns out to be one that was prohibited for use.

It contains a mysterious switch button that you're not supposed to turn on for any purpose at all.

Like any horror plot, someone has to push it.

That someone is you -- or anyone brave enough to room with you -- because obviously, you paid for the room.

[caption id="" align="alignnone" width="1000"] Image via Hotel Universal Port Halloween's Twitter[/caption]

The button essentially activates the horror elements in the already spooky room, which may come from any corner, and where you may not expect, like a surreal Russian roulette.

What to expect

Since the theme changes every year, no one knows what to expect from this room just yet, but footage from the initial run in 2015 reveals much to be spooked about:

Spooky spirit seals, campy bloodstains calling for help and severed plastic limbs might cheese some off at first, but guests will soon realise that it wasn't just a half-hearted Halloween party, but something that went very wrong on Halloween itself.

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Feel like someone's watching you? Don't turn back when you shower, because you'll see a silhouette staring right back at you:

Given that the image preview for this year's horror room looks to be toned down, we imagine plenty of nasty surprises to happen.

The hotel runs from Sept. 1 to Dec. 20, so there's plenty of time for you and your friends to plan that trip if you happen to be around Osaka, Japan at that time.

There are limited rooms, so book early.

Details

Address:

Hotel Universal Port 

1-1-111 Sakurajima, Konohana-ku,

Osaka city, Osaka

Zip:554-0031 Japan

Date: Sept. 1 - Dec. 20 2018

Price: 9,500 yen - 34,500 yen per person, per night, depending on the number of guests (approx. S$116.20 per person to S$421.98 per person, per night)

Breakfast is included.

Rooms available: 3 rooms -- 1 room for 2 guests, 1 room for 3 guests, and 1 room for 4 guests.

Each room is 40 square meters. All are non-smoking.

Booking: reservation to be made online only.

All guests need to be 15 years old and above.

Top image via Hotel Universal Port's website