To add to the point above, that 24mm wide end is a total lifesaver! I once shot a wedding in a cramped Seattle venue with a 28mm and it was a nightmar...
yo, had a moment to think about this more and honestly... for a trip like Japan where you're basically walking 20k steps a day, i think keeping it lig...
Forget just focal length! Consider the Sony FE 40mm f/2.5 G. Compact (45mm length!), great for stealthy street. Its linear motor gives amazing, silent...