Ive been thinking about your Tokyo trip and honestly, I went through the same adapter headache when I first jumped to the R system. For a pro body like yours, you really need the Canon RF 24-70mm f/2.8L IS USM. I spent a month shooting around Shinjuku and the focus tracking on the R5II with this native glass is just... night and day compared to the EF stuff. No more hunting in those tricky neon lights. Heres why I'm so happy with it:

• Nano USM motors are basically silent and instant for fast street work.
• f/2.8 gives you that subject separation for portraits that the cheaper zooms just cant touch.
• The internal stabilization works with the R5II IBIS so well you can shoot handheld at crazy slow shutter speeds. Itll eat most of your 3k budget, but for a one-lens setup, its the gold standard. Just grab a good filter and youre set.

Jumping in real quick because I basically live for these kinds of gear dilemmas. Like someone mentioned earlier, that 24-70 is a beast, but if youre doing street work in Tokyo, sometimes you need more than 70mm without swapping lenses in a crowded station. Shooting there last fall taught me that reach is king. I found the Canon RF 24-105mm f/4L IS USM to be a lifesaver for weight, and it leaves you tons of cash for the rest of the trip. But honestly, since you have a 3k budget, you should check out the Canon RF 24-105mm f/2.8L IS USM Z. It is a bit of a brick, but it combines the low-light perks of the 24-70 with the reach of the 105. Its basically the gold standard for native glass right now on the R5II. Tracking is insane and it doesnt hunt like the adapted stuff. If the size of the 2.8 Z is too much, the Canon RF 24-70mm f/2.8L IS USM is still the safer bet for portraits tho. Just depends if you value the extra 35mm of reach or a lighter bag.

My current setup is a decent native zoom option. It worked great for street.

• faster tracking
• zero hunting Native glass beats adapters tho. Primes are another alternative. Ask more if needed!