The Best Water Setup for a New Apartment

You've just moved into a new apartment in Japan, and the to-do list is long: register your address, sort out internet, pick an electricity plan, figure out gomi (ゴミ, garbage) sorting rules. Somewhere on that list, a nagging question shows up: what do you need to do about water? The honest answer is: almost nothing. Japan's tap water is already safe to drink straight from the faucet, in the vast majority of buildings it's already connected when you arrive, and the only real decisions are small, cheap ones you can make in your first week rather than your first hour. This guide walks through what actually matters on day one, what's worth spending a few thousand yen on, and the one water-related decision — a water server contract — that's worth slowing down on before you sign anything.

Your tap is already safe and on (day one)

Unlike some countries where you might need to boil or filter water before you can trust it, Japan's tap water meets strict national standards essentially everywhere, from central Tokyo to small regional towns. If you want the detail on why that's true and how it's tested, see why the tap is safe. For move-in purposes, the practical point is simpler: water is almost always already connected to the unit when you move in, and your job is administrative rather than physical. You (or your real estate agent) file a start-of-use notice with the local 水道局 (suidōkyoku, water utility bureau) — often by postcard left in the unit, phone call, or online form — so that billing starts in your name. That's it. There is no need to buy a case of bottled water "just in case" while you wait for water to be turned on; in nearly every apartment, it already is.

The cheap default setup: kettle, plus an optional filter

For the overwhelming majority of new residents, the right water setup costs a few thousand yen and takes ten minutes to buy. An electric kettle (denki kettoru) runs roughly ¥3,000–6,000 and covers tea, coffee, instant noodles, and general boiling. If you don't already own one, it's the single most useful small appliance to buy in your first week, right alongside a rice cooker.

Beyond that, a filter is optional, not required. Some people simply prefer the taste of filtered water, and if you're in an older building or one with a storage tank (more on that below), a filter is a reasonable extra layer of comfort. A filter pitcher costs about ¥2,000–4,000 up front, with replacement cartridges around ¥1,000–1,500 that each last roughly 150 liters — working out to roughly ¥6–8 per liter over the cartridge's life. A tap-mounted filter is a similar cost structure. Either option is a "nice to have," not a safety requirement; it's about taste preference, not water quality. If you're curious how mineral content and taste vary by area, taste and hardness by region covers that in more depth, since it's often the real reason people reach for a filter rather than any concern about safety.

If your building uses a storage tank (受水槽)

Some older apartment buildings, particularly larger ones, don't feed tap water directly from the mains — instead water passes through a rooftop or basement storage tank called a 受水槽 (jusuisō) before reaching your unit. The water itself is still treated to the same national standard, but water that's been sitting in a tank for a while can pick up a slightly stale taste, especially after you've been away for a few days. The simple fix is to run the tap for a few seconds before drinking or cooking with it, to clear out standing water in the pipes. If you'd rather not think about it at all, a filter pitcher handles this too. Either way, this is a taste and freshness consideration, not a safety one — the mains water going into the tank is already up to standard.

When a water server actually makes sense

Water delivery servers — the large bottle-and-dispenser units you'll see advertised everywhere — are a genuine option for some households, but they're not the default most people need. They tend to make sense if you have a specific, real use case: you drink a lot of hot water or tea throughout the day, you're preparing baby formula and want convenient hot and cold water on tap, you have mobility issues that make carrying water bottles difficult, or you're setting one up for an office rather than a single-person apartment. If none of those describe you, a kettle and maybe a filter will save you money and commitment.

If you do decide a server is right for you, the one thing not to skip is reading the contract terms before you sign — and specifically not signing one in the rush of moving week, when a sales rep at the real estate office or a flyer in your mailbox makes it feel like just another box to tick. Most server plans come with a minimum contract term (often one or two years) and a 解約金 (kaiyakukin, cancellation fee) if you cancel early, typically somewhere between ¥5,000 and ¥30,000 depending on the provider and how early you cancel. That fee structure is exactly the kind of thing that's easy to gloss over when you're signing five things in one afternoon. For a full breakdown of what servers actually cost once you include the machine, the water, and the contract terms, see the water-server true cost before you commit to anything.

Batch it with your other move-in setup tasks

Water is really just one line item in a bigger move-in checklist, and it's worth handling it alongside the others rather than in isolation. If you haven't already worked out your overall move-in budget, a Japan move-in cost calculator is a useful way to see where money is actually going in your first month. The same week you're deciding about a kettle versus a filter is usually the same week you're also comparing options for setting up home internet and choosing an electricity plan — all three are day-one administrative tasks with similar rhythm: a bit of research, a form or a phone call, and then you're done for a year or more. None of these need to be rushed or bundled together through a single salesperson; treating them as separate small decisions, made calmly, tends to produce better outcomes than signing whatever's offered on move-in day.

The short version

On day one, your water is already safe and very likely already connected — you just need to file the start-of-use notice with your 水道局. Buy a kettle, consider a filter if you like the taste better or you're in a tank-fed building, and only look at a water server if you have a genuine reason to need one, reading the cancellation terms carefully before you sign. If you want to see how these small costs add up against everything else in your move-in budget, the cost calculator can help, and the FAQ covers other common move-in questions. This page is informational only, not professional advice, and specific procedures can vary by municipality and building — confirm details with your local water utility or landlord where it matters.