You assign blocks of numbers along a road, eg by thousands. So a block becomes the "300 block". Within that block you allocate odds on one side, evens on the other. Then you assign numbers with gaps between them to account for future changes. Basically take the length of the block, divide into 50 "lots" per side, and give each one a number. So a building with its centerpoint at the midpoint of the block on the north side of the road gets the number 350. The building next to it can get 340. If that building is replaced by two buildings you can use 342 and 347. If one of those becomes a duplex 347 becomes 346/347. There is no confusion: any address with a 3xx number is on this specific block, with the lower numbers near one end of the block and the higher numbers on the other end.

If you find block 300 you also know roughly how far away block 9000 is and you know what direction to go. Or in the worst case when you see that the next block is all 2xx buildings you know you are going the opposite direction so you turn around.

This is the typical western street numbering design. There are variations - sometimes streets start at the center and indicate direction, so West Easy St vs East Easy St both start at 100 or 1000 and count up. But in general if you can find the street you want at any point along its length you can very quickly determine which direction to go and approximately how far.

To help orient you cross streets can be provided. If you know Avenue H intersects with Jones St then you cannot get fully lost. If you move up and down Ave H you will eventually find its intersection with Jones St and from the number you can determine which direction to go along Jones St (or someone can tell you Jones at 5000 block of Ave H).

Many cities go further and have a letter/number grid system to their roads that takes the same concept up a level: giving numbers, letters (or words starting with the relevant letter in alphabetical order). Minor roads might be named but move to the next intersection of any of them and you arrive at Ave H or 132nd St. And from there you know which direction to go and approximately how far to find 18th St or Ave A.

I'm not saying Japan should have adopted this specific system. But they certainly could have come up with a system that had some kind of scheme to it designed to help people figure out "if I am here which direction should I go to reach my destination?".