Potentially travelling to Japan in July for the first time

Hello, first off – I know that its going to be crazy hot and humid (that much is clear lol) but I want to know if its going to potentially ruin the trip…
My wife and I (both in our late 20's) have not really travelled outside of the UK before. Japan has always been the dream. We are hoping to spend 10 days between Tokyo and Kyoto in mid July. Has anyone from the UK (or similar climates) any advice based on their experience? Due to our work, its really the only month we can make work for the foreseeable.
Any comments/advice is welcome. Thank you!

by EmployAdditional3406