You move into a Japanese apartment, drop your bags, and start looking for the thermostat.
There isn’t one.
What you find instead is a white box bolted above the window and a plastic remote sitting in a little holder screwed to the wall next to the light switch. That remote is the entire user interface for climate control in that room. Lose it and you’re pressing the emergency button on the indoor unit.
I got a question about this from someone on r/japanlife who’d lived in six different apartments here, all built in the last 30 years, and had never once seen a wall thermostat. He wanted to put in a smart one. He couldn’t, and the reason why is worth understanding before you spend money trying.
Why the wall is empty
A thermostat exists to close a loop. It measures the air in one place, decides the whole house is too cold, and tells a furnace or a central air handler somewhere else to do something about it. It needs a central plant and ducts to be worth wiring to a wall.
Japanese apartments mostly don’t have either. What you get is a ルームエアコン, a room air conditioner: an outdoor compressor and an indoor unit serving exactly one room. A 2LDK with three of these has three independent heat pumps that don’t know the others exist.
The temperature sensor already lives inside the indoor unit, in the air intake at the top. That’s the thing reading your room. The remote tells the unit what number to aim for and what mode to run, then goes quiet. Think of it as the keyboard, sitting outside the control loop entirely.
So there’s nothing on the wall to replace. Swapping a Nest into a Japanese apartment is like buying a steering wheel for a bicycle.
Some newer, more expensive buildings do have 全館空調 (whole-building climate systems) and some higher-end aircon models let the remote act as the temperature sensor instead of the indoor unit. Those are the exceptions. If you’re renting a normal 1K or 2LDK, assume the setup above.
What that gets you, and what it costs you
The per-room design is a different set of tradeoffs, and living with it for my whole life, I’ve come to like most of them.
You only pay to condition the room you’re in. An empty bedroom in a Japanese apartment costs nothing all day. My old place in Malaysia also rarely use central air-conditioner, as people get an air-con for a room when their financial ability improves over the years. In some commercial building with central air conditioning unit, you could only control flap that ajust the vane of the duct sending the central air to the space.
Each room can be at a different temperature, which matters when one person sleeps at 26°C and the other wants 24°C.
The cost shows up in a few places. You can’t warm the whole apartment before you get out of bed. Every unit has its own remote, so a 2LDK with a TV means four remotes on the coffee table. And the hallway, the toilet and the bathroom get nothing at all, which is how Japan ends up with a genuine winter problem in the parts of the home that don’t have a box above the window.
That’s the gap a smart remote fills.
What a smart remote actually is
It’s an infrared blaster with Wi-Fi. It sits in your room, you point your existing aircon remote at it and press a button, it learns or matches the code, and from then on your phone can send the same infrared commands from anywhere.
The aircon has no idea anything changed. As far as it’s concerned, someone in the room pressed the remote. There’s no wiring and no drilling, so there’s nothing for your landlord to object to when you move out. This is the most rental-friendly upgrade available in a Japanese apartment.
Once the hub knows your aircon, you get the things the plastic remote can never do: turn the bedroom on from the train, run the living room on a schedule, trigger cooling when the room passes a temperature, control it by voice through Alexa or Google or Siri, and put the TV and the ceiling light on the same app.
Infrared only goes one way
Your hub can shout at the aircon. The aircon never answers.
So the app is showing you the last thing the hub told the unit to do, which stands in for the real state right up until the two drift apart.
Get up in the night, grab the physical remote, turn the unit off, and the app still thinks it’s running at 26°C in cool mode. Tap “off” in the app the next morning and you’ll turn it back on, because the hub sends the off command to a unit that’s already off. Some aircons treat that as a toggle.
Two habits fix most of this. Pick one control method per room and stick to it, and when things get out of sync, send a full command from the app (mode plus temperature) rather than a power toggle, since that resets everything to a known state.
The second constraint is physical. Infrared doesn’t go through walls, and Nature says so on their own product page: one unit per room, regardless of the rated range. That matters for the budget. A 2LDK where you want app control in the living room and both bedrooms is three hubs, not one.
What to buy, with real prices
Prices below are what Amazon Japan was charging on 2026-08-10. Smart remotes get discounted often, so check before you buy.
Nature Remo nano, ¥4,980
The cheap one. No sensors at all, an infrared range of about 10 jō, and automation limited to time, day of week and your phone’s GPS location. It supports Matter, so it shows up natively in Apple’s Home app and can bridge up to 3 infrared appliances into it.
Buy this for a second bedroom where you want remote on/off and nothing clever.
Nature Remo mini 2, ¥6,480
Adds a temperature sensor and an infrared range of about 30 jō. That sensor is the whole point, because it enables “if the room goes above 28°C, turn the aircon on,” which is the one automation people in Japan use every August. No Matter support.
Nature Remo 3, ¥6,480
Four sensors: temperature, humidity, illuminance and motion. Nature lists it at ¥9,980 on their own store, and Amazon had it at ¥6,480 the day I checked, which makes it the strangest deal in the category. It’s the only model that can trigger on movement or on the room getting dark, so it’s the one to get if you want the lights to come on when you walk in.
The catch is no Matter, so Apple Home users are stuck with Nature’s own app plus Siri Shortcuts.
Nature Remo Lapis, ¥7,480
Temperature and humidity sensors, 30 jō range, and Matter support for up to 20 appliances, which is the highest in the range. It won a 2024 Good Design Award and looks like a smooth grey stone, which sounds like marketing until you see it next to the beige plastic remote it replaces.
This is the one I’d point Apple Home users at.
SwitchBot Hub 2, ¥9,980
The most capable and the most expensive. Temperature and humidity sensors sit in the attached cable rather than the body, which keeps your own body heat and the unit’s electronics out of the reading. There’s a display on the front, a light sensor, Matter support, and an infrared database SwitchBot claims covers 4,877 manufacturers, 21,363 remote types and 83,934 model numbers.
Get this one if you already own SwitchBot gear, since the hub is what puts their Bluetooth-only devices (curtain openers, the lock, the button pusher) onto Wi-Fi and into Matter.
The manufacturer’s own Wi-Fi adapter
Daikin, Panasonic and Mitsubishi all sell official Wi-Fi kits for their aircons, and they solve the feedback problem properly. The adapter talks to the unit’s own control board, so the app knows the real state, reads the real room temperature, and can show error codes and power consumption.
Then you look at the price. Daikin’s BRP087A42 adapter runs about ¥12,220 to ¥14,670 depending on the shop, and that’s for one air conditioner. It’s a separate purchase from the aircon, it has to be fitted inside the indoor unit, and on some models that’s a job for an installer rather than a Saturday afternoon.
A Nature Remo nano is ¥4,980 and does the aircon, the TV and the ceiling light in the same room. For most renters that’s the end of the argument.
The official adapter earns its money in two situations: you own the place and plan to keep that aircon for a decade, or you want energy data and fault reporting rather than just a remote. Nature also supports some manufacturer-specific functions for Daikin, Mitsubishi and Panasonic units, so check their compatibility page for your exact model before assuming you need the official kit.
If you’re still choosing the aircon itself, I went through what the specs on the box mean in why Japanese air conditioners look different from the rest of the world, and the basics of buying one for a new apartment are in my guide to getting an air conditioner when you move to Japan.
Automations worth setting up in a Japanese apartment
Four of these have survived on my phone for longer than a month. The rest I turned off.
Turn on above 28°C. Japanese summers hold 33°C and 70% humidity for weeks. A temperature trigger means the room is survivable when you walk in without leaving the unit running all day. Any model with a temperature sensor can do this.
Dry mode above 60% humidity. June and July punish you with humidity long before the temperature becomes the issue. Nature’s own automation examples list this exact rule. Watch the running cost though: 除湿 (dry mode) on many units is a re-heat cycle that costs more per hour than plain cooling.
GPS on the way home. Set a radius around your apartment and let the aircon start when you leave the station. In a small room a heat pump gets there in about 10 minutes, so this is the difference between walking into 34°C and walking into 27°C.
A hard off at bedtime. Every aircon has a sleep timer. The advantage of doing it from the hub is that it also kills the TV and the lights.
Before you buy, check these
Your Wi-Fi has a 2.4GHz band. Every hub here is 2.4GHz only. If your router is running a combined 2.4/5GHz network under one name, some setups need you to split them temporarily to get the hub connected.
Your remote is infrared, not Bluetooth. Almost all Japanese aircon remotes are infrared. If yours is Bluetooth or Wi-Fi (rare, and usually on premium models with their own app), none of these will work. Point your phone camera at the remote’s emitter and press a button: if you see a purple flash on screen, it’s infrared.
Your aircon’s age doesn’t matter. Infrared is infrared. A 2008 unit works exactly as well as a 2026 one, which is the quiet advantage of this whole approach over the official Wi-Fi adapters.
Line of sight to the unit. The hub needs to see the aircon. Behind the TV, inside a cabinet, or across a wall from the unit means it won’t work reliably.
What I’d buy
For a single room where you want the automation, the Nature Remo 3 at ¥6,480 is hard to argue with, since you get four sensors for the price of a mini 2. If Apple Home is your ecosystem, pay the extra ¥1,000 for the Lapis and get proper Matter support. For a spare bedroom, a nano at ¥4,980 does the job.
And if you already have SwitchBot curtains or a SwitchBot lock, buy the Hub 2 and stop reading.
A Japanese apartment will still heat and cool one room at a time, the way it was designed to. What changes is that each room’s plastic remote becomes something your phone can reach from the train, for less than the cost of one official Wi-Fi adapter, without a single screw going into a rented wall.
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