Using a Japanese Bathroom: Bidet Toilets, Bath Reheating and Water Heater Panels

Updated: 2026-09-17

Quick answer

Miya, the GetConnectedJapan guide, smiling warmly and giving a small friendly wave in a bright everyday setting. — Once you know a handful of symbols, the bathroom panels in a Japanese flat are easy to use.

Hi, I'm Miya, and I help newcomers settle into life in Japan. The bathroom in a Japanese apartment can feel like a small control room: a toilet seat with a row of buttons, a wall panel that talks to you, and a fan switch with several modes. None of it is difficult once you know what the symbols mean. This guide is about everyday use of that equipment; for public bath etiquette or what to do when something breaks, we have separate guides.

The short version: on the bidet toilet, 止 means stop, and most wash buttons only work while you're seated. To run a bath, put the plug in, press the button marked ふろ自動 or 自動, and the system fills and heats the tub for you. 追いだき reheats water that has cooled, and the panel's main display sets the hot-water temperature for your taps. Keep the ventilation fan running after bathing and rinse the walls with cool water, and you'll stay a step ahead of mould.

Reading the bidet toilet control panel

Most homes have a warm-water bidet seat, called onsui senjo benza (温水洗浄便座) and often referred to by a brand name. The controls are either on a panel beside the seat or on a remote mounted on the wall. The most important button is 止 (stop), usually orange or red, which ends any wash function. おしり (oshiri) is the rear wash, ビデ (bide) is the front wash designed for women, and 乾燥 (kansō) is a warm-air dryer on models that have one.

You'll also see 水勢 (suisei) for water pressure, often shown as plus and minus or a row of bars, and 位置 (ichi) for moving the nozzle forwards or backwards. The 便座 (benza) and 温水 (onsui) settings adjust the seat and water temperature, and 節電 (setsuden) is a power-saving mode that may leave the seat cool. Many seats have a sensor, so the wash buttons won't respond unless someone is sitting down, which is a safety feature rather than a fault. If you're ever unsure, press 止 first; it's always safe.

Flushing and everyday toilet habits

Flushing is sometimes separate from the seat panel. On a tank with a lever, 大 (dai, large) is the full flush and 小 (shō, small) is the lighter one, and the direction to turn is marked beside each character. Some toilets have a flush button on the wall remote, labelled 流す (nagasu) or with the same 大 and 小, and some flush automatically when you stand up. The small basin on top of some tanks runs clean water for washing your hands while the tank refills.

Only toilet paper should go down the toilet; tissues, wipes and sanitary products usually go in the bin, because pipes can block easily. Many seats have a nozzle-cleaning button, often labelled ノズル洗浄 or ノズルきれい, which is worth using now and then. If the seat stops responding, check that its plug is in and the panel isn't in power-saving mode. In a power cut the seat functions won't work, but a lever tank can often still be flushed — check your model's manual for the details.

The unit bath and how bathing at home works

Many apartments have a unit bath (ユニットバス), a moulded, waterproof room built as one piece. In smaller studios the toilet, basin and bathtub may all share one room, while listings marked バス・トイレ別 (basu toire betsu) have the toilet in a separate room. In a Japanese-style bathroom with a washing area (洗い場, araiba) outside the tub, you wash and rinse off first, then soak in clean water. That's why the bath water stays clean, and in some households it's kept warm and shared by everyone.

In a combined room without a washing area, people usually shower standing inside the tub with the curtain tucked inside it, so the water drains away and the floor stays dry. The floor of a combined room often has little or no drain, so a splashed floor can stay wet for a long time. Put a bath mat just outside the door, and keep towels and toilet paper away from the shower spray. Whether you drain the tub after each bath or keep the water to reheat is up to you, but water that has been sitting a long time is best drained and the tub rinsed.

Filling and reheating the bath: the bath panel

Many apartments have a bath control panel, usually one on the bathroom wall and one in the kitchen. First, make sure the plug (栓, sen) is in the drain. Then press ふろ自動 (furo jidō) or 自動, and the system fills the tub to the set level and heats it to the set temperature; a chime or voice announcement tells you when the bath is ready. The water level is usually set under 湯量 (yuryō) or ふろ湯量, and the bath temperature under ふろ温度.

追いだき (oidaki, also written 追い焚き) reheats water already in the tub by circulating it through the water heater. For this to work, the water must be above the round fitting in the tub wall, called the circulation port (循環口, junkankō), so don't press it on an empty or nearly empty tub. 保温 (hoon) keeps the bath warm for a while after filling, and some panels have たし湯 (tashiyu) to add hot water. Some bath salts and powders aren't suitable for reheating systems, so check the manual before using them.

Water heater settings and panel messages

The button labelled 運転 (unten) or 給湯 (kyūtō) turns the water heater on, and in many homes the taps only run hot while it's on. The number on the display is the hot-water temperature sent to the kitchen and bathroom taps, and many people keep it somewhere around 40°C for everyday use. Some people raise it a little for washing up, but a very high setting can scald at the shower, especially for children. If your panels have a 優先 (yūsen, priority) button, the panel where it's lit controls the temperature, which explains why pressing buttons in the bathroom sometimes seems to do nothing.

If something goes wrong, the display usually shows an error code, and some panels also give a voice message. Write the code down or take a photo, then look it up in the manual (取扱説明書, toriatsukai setsumeisho), which you can often find online by searching the model number printed on the panel or the heater. The manual sometimes suggests a simple step, such as switching the heater off and on again. If the code keeps coming back, contact the management company, and if you ever smell gas, stop using it, open a window and contact your gas provider straight away.

The ventilation fan, bathroom dryer and mould-free habits

Bathrooms in Japan are humid, and mould (カビ, kabi) grows quickly, especially during the rainy season. Many apartments have a ventilation system meant to run all the time, sometimes labelled 24時間換気 (24-hour ventilation), and it's generally best to leave it on. If your bathroom has a heater-dryer unit (浴室換気乾燥機), its panel will show 換気 (kanki, ventilation), 乾燥 (kansō, drying), 暖房 (danbō, heating) and sometimes 涼風 (ryōfū, cool air), along with a timer. The drying mode lets you hang laundry in the bathroom on rainy days, using the pole or rail near the ceiling.

A few small habits make a big difference. After the last bath of the day, rinse the walls and floor with cool water to wash off soap and bring the humidity down, then wipe or squeegee off what you can and leave the fan running. Clean the hair catcher in the drain (排水口, haisuikō) regularly, and wash the tub while it's still warm and grime comes off easily. When using cleaners, never mix chlorine-based products (塩素系) with acidic ones (酸性); Japanese packaging carries the warning 混ぜるな危険, meaning dangerous if mixed.

Symbols, calls and a Japanese line for your first week

In your first week, a camera translation app on your phone is the quickest way to read an unfamiliar panel: point it at the buttons and the labels appear in your language. When a setting won't work or a code keeps appearing, the management company (管理会社, kanri gaisha) or your landlord is usually the right first call, and they'll often want to ring you back. That's where a Japanese phone number with data really helps, so you can look things up at home and pick up when they call. Setting one up is simple — you apply online with your residence card, verify with a quick eKYC, and eSIM-capable phones can often connect the same day in about fifteen minutes.

Have a look at our setup guide for eligibility and the step-by-step, and confirm current terms on the page before you apply. Once you know 止, 自動 and 追いだき, the bathroom stops being a puzzle and becomes the most relaxing room in your home. I'll be right here to help.