Noise disclosure laws when buying a house?

I'm sure every country has different noise disclosure laws when a private seller or a realtor sells a property and I wondered what the situation is in Japan.

Are realtors legally obliged to inform buyers about noisy businesses or neighbors?

And even if they technically are, would these laws ever be really enforced in Japan? I guess it is well known that there can be many noise pollution issues that are never acted upon even though there are technically anti-noise pollution laws.

Many thanks for any advice you can give.

If you are buying property, you should be doing your own research. Someone selling a house might have no idea what the neighbours are like (and they change anyway).

Certainly one of the places I looked at a few years back here in Tokyo I turned down because of the bar across the street hosting live music each weekend.

When I bought our house in Japan we choose outside the city and close to the Station.
So far I have no problems with noise or pollution.

Often pending on the budget or requirements of the buyer you can have noisy place till a really quiet neighborhood

They are required to disclose information that would materially impact the value of the house/property, but as many other laws in Japan, it is not really "enforced," or should any problem arise after the purchase, it is not easy to resort to legal solution. Also, if neighbors move in/out, the situation can change.

What you can do is maybe borrow the house key for a while, maybe stop over the house at night/different days of the week, and check the noise/life patterns of those around the property. Also check the zoning as well - residential only, commercial district, "light industrial," etc. Like the block our apartment building is on is residential, but the section facing the main street is light industrial/commercial, meaning they can operate shops, restaurants, commercial establishments, which so far included wood workshop (some sawing noise), garbage processing (small trucks going in and out), karaoke bar, restaurants, etc.

「Are realtors legally obliged to inform buyers about noisy businesses or neighbors?」

Not really. Nearby businesses should be a matter of public record, and as for (non-commercial) neighbors, there's no official/legal determinant of what constitutes "noisy," so even if such a law existed, it wouldn't be enforceable.

If possible, the best thing to do is to check out the property not just in the afternoon, but also at night (and possibly early morning if noise levels then are also a concern for you). That'll give you a better idea of what living there day in and day out will feel like. I did night visits (of the building exterior) for the last two apartments I moved into, and I'm glad I did.

However, be aware that Japanese zoning laws are fairly lax about prohibiting commercial use, and also that the country's small property lots mean you'll likely be very close to the neighboring properties. As such, the fact that your neighbors are quiet now may not be a guarantee that they'll be quiet in the future. My current apartment use to have a nearly empty parking lot next door, which has now been turned into a multi-story retirement home, and the vegetable patch that was down the street for the last 10 years is now a convenience store.