What I meant is that in japan, zoning laws are never just for a single thing, and instead are essentially just a "maximum nuisance allowance," as it were, instead of the city planners having to micromanage exactly what gets put where. for example, you can't build high rise commercial buildings in an area zoned for low density residential, however there's absolutely nothing stopping you from doing the opposite. Additionally, there's far fewer restrictions when it comes to what kinds of housing you can build in various areas, for example in America you have huge swathes of land dedicated purely to detached single family housing, but in japan the same low density residential area can house single family, duplex, and even small apartment buildings.
Personally I'd prefer that they be even more hands off but it's certainly still worlds better than the Euclidian housing schemes we get in America.https://urbankchoze.blogspot.com/2014/04/japanese-zoning.html
this link explains it better than I could, and I suggest that you read it.