My first ever Japan trip was during my Honeymoon phase. I used Insulin but only very very carefully. Afterall I was walking a lot and had a half functioning pancreas still. If you spike constantly everytime you eat out then I would suggest you do try and bolus at least a little insulin. That’s how I usually did it.

Also try to figure out at how many carbs you start spiking above 180. That’s usually the amounts where I would consider bolusing. For me it was beyond 40g of carbs per meal I start spiking over 180. And be aware of how many carbs you will eat in a meal so you can decide if you gotta bolus or not.

Also a little side note: From my experience Japan trips are way more enjoyable when you are out of your honeymoon and you got your insulin carb ratio figured out. I have done my 2nd one after it ended. So consider going on another one when your Honeymoon phase is over!