Regarding what #1 said about prioritizing protection, in my experience, comfort actually starts with the ergonomics of the camera body itself. The X-T5 is a great size but it is honestly a bit too slim for all-day street shooting in a place like Japan. Over the years, I've found that adding a dedicated grip is basically non-negotiable for long days on your feet. I highly recommend the Fujifilm MHG-XT5 Metal Hand Grip. It gives you a much better hold without blocking access to the battery door, which is a common flaw with cheaper third-party options. It makes the camera feel way more professional and secure in your hand while you are navigating crowds. Safety is the other big thing I prioritize. Since you are new to this, you are probably gonna be swinging the camera around and occasionally bumping into things in crowded train stations or narrow alleys. I never leave the house without a high-end clear filter on my glass. Check out the B+W 58mm Master Clear Filter MRC Nano or whatever size matches your specific lens. It protects your expensive glass from scratches and dust without degrading the image quality like the cheap plastic ones do. Lastly, grab something like the Lensmate Soft Release Button Brass. It screws into the shutter button and gives you much better tactile feedback when you're trying to time a shot perfectly on the street. It sounds like a tiny thing but it really changes how the camera feels when you're firing off shots.

In my experience, you really need to prioritize protection and power when traveling. Japan involves a lot of walking and you dont want your gear failing. First thing is a screen protector. I always use Expert Shield Screen Protector Fujifilm X-T5 Glass because it keeps the resale value up and prevents scratches. For comfort, skip the neck strap that came in the box and get Peak Design Slide Lite Camera Strap Black. It is way more reliable for carrying the camera all day while doing street photography. I have tried many cheap third-party batteries over the years and they usually swell or die early. Stick with an official Fujifilm NP-W235 Rechargeable Li-Ion Battery. It is much safer for the camera internals. Since you are on a budget, grab a reliable SD card like SanDisk Extreme Pro 128GB SDXC UHS-II V60. It is plenty fast for street shots without the V90 price tag. This combo will keep you safe and well under that $250 limit.

^ This. Also, jumping in here... looks like we've covered the basics for ergonomics and battery life pretty well. Since you're traveling to Japan, reliability is what really matters most to me. I've been shooting for a decade and I'm always satisfied with a setup that prioritizes safety and cleanliness. Grab a Giottos Rocket Air Blaster Large to deal with street dust. It works well and I've had zero complaints after using mine for years. Also, for safety, look at the Think Tank Photo Mirrorless Mover 20. It fits the X-T5 perfectly and keeps it protected from bumps or a light drizzle while you're walking. It's affordable and stays way under your budget. Keep it simple, keep the sensor clean, and you'll be happy you didnt overcomplicate things.

Ngl I'm in the exact same boat. Just picked mine up and I'm heading to Osaka next month too. Total analysis paralysis over here... Spending so much on the body left my bank account looking pretty sad. Last time I traveled, I overpacked so much gear that I ended up leaving half of it in the hotel room. It's a real struggle finding that balance between being prepared and staying light tho.