Looked it up, didn't find much but did find this, these look like made of stone indeed but maybe it's because they're thinner? When I think of stone houses I think of things like this with very thick walls, we have these in all the really hot countries like Italy, Spain, southern France etc and I can confirm they stay cool inside even when it's 40°c outside.
Our brick is usually brick, then some wood frame bolted to that, then insulation in the gaps, and dry wall. The insulation is pretty good, but the issue is usually the roof, and the windows being older than double pane tech. So they let the heat in and then cook, badly.
But yeah we don't have much stone like that picture. Usually we use concrete if we want walls that thick. Concrete + HVAC works very well here because there's not a lot of humidity.
We mostly stopped using brick though because earthquakes annihilate brick buildings even after reinforcement. The only thing timber seems to be good at is resisting those.
You're describing "brick veneer" construction - with one skin of bricks and an internal timber frame - which, as you've apparently experienced, is not very effective at keeping the space cool (although probably better than timber/stucco cladding). Solid masonry is usually two skins of brick with a cavity or equivalent thickness of concrete / stone block exterior walls.
No they're old houses made from brick that later had a timber frame retrofitted internally to run electrical and HVAC. The frame just holds up false walls. I'm mainly talking about old houses here
If it was solid stone (thickness of two brick skins) with additional insulating material behind the tacked on plasterboard then I'm surprised to hear that it didn't stay reasonably comfortable in hot weather and would suspect other factors, such as metal roofing and/or inadequate ceiling insulation may be the reason for that.
Yep earthquakes are basically non-existent in these parts so it's not a factor, I think the Japanese have a bunch of techniques for concrete buildings that survive earthquakes and special building codes so the structure can move etc. Older roofs are definitely a problem here as well but if it's less than like 10/20 years old then it'll also have all the good insulation stuff.
Yeah concrete holds up very well with modern construction thankfully. But our building codes don't have shit on the Japanese. Their earthquake resistance is magic to me