Water refilling station business

I searched that tap water are safe to drink in Japan but is water refilling station common there? or are they used to just buy bottled water in convenience stores/dispensing machine?

A lot of supermarkets have something like that. I've never used it, but I believe you usually purchase a big plastic bottle for a price, and then you can get water for free from a machine specifically for that purpose, as long as you're using that bottle. I commonly see people obtaining the water when I go shopping for groceries.

There are also delivery service similar to the American Sparkletts in which you purchase a machine and they'll deliver the huge water bottles for you. I often see them in shops and cafes, but I've never really seen them at an ordinary household.

or are they used to just buy bottled water in convenience stores/dispensing machine?

Who do you mean by "they"? I don't know what foreign tourists do, but locals like me would buy bottled tea unsweetened instead. At home, a lot of people just use water from the tap, or they'd have a purifier attached to the faucet. It also may depend on the region or building, because water in some regions have better reputation than others while water pipes in older buildings tend to get more rusty and less tasty.

I personally don't know who would subscribe to such a business. As you mentioned, tap water is safe to drink in Japan, and vending machines are everywhere where you can buy water/soda/tea/beer/etc. And Japan also has lots of "famous" spring water that you can bottle for free.

I use my local supermarket's water station, and judging by the line every time I do, plenty of other people do as well! They are very common in grocery stores where I live. The one I use has you buy a plastic bottle from the store which you then use to refill for free. At a different grocery store, you can refill the large-type pet bottles for free.

We used to have a big water dispenser using spring water that was delivered each month, but even though we got the unit for "free" from a contest, it was 2000 yen per bottle, with a minimum of 2 per order per month, so that was 4000 yen minimum every month. If we had had to rent the unit it would have been more. So it's pretty expensive just for personal use.

The tap water where I live is hard water and has an after-taste. Fine for cooking, but I don't like drinking it straight. Even if you buy bulk bottled water from Costco, it is still much cheaper in the long run to buy the supermarket bottle and just refill, and less plastic to recycle, too. I got the bottle for around 300 yen as there was a promotion going on; usually the bottle is around 500 yen for a good size.

2-3 bottles last a week for us, but we use the water for more than just drinking, including for our fish tanks because it is filtered and un-chlorinated. I definitely recommend it if you live near a supermarket that has the service!

Hi again. As kanda m pointed out, I think Japan doesn't have a real water refilling "station" industry, not because tap water is safe but because vending machines work. We don't see real humans setting up individual stations just to sit there all day long selling water. They leave it to the machines that also sell other things or can be placed in a store that sell other things, and let drivers come around every once in a while to supplying the machines.