Hello,
Thank you for mapping Japan.

You added some buildings, but you didn't square them.
https://osmcha.org/changesets/170424251

In the real world, most buildings have right-angled corners, so we need to reflect that on the map. But it's difficult for us to draw them freehand.

So please use the 'Q' key on your keyboard to square the corners of the building.

Common New Mapper Mistakes: Buildings not Squared or Circularized (YouTube)
https://www.youtube.com/watch?v=Xs5wX592E1o

Common New Mapper Mistakes: Connected Nodes (YouTube)
https://www.youtube.com/watch?v=ltn1VOiq5_0

Happy Mapping!
