Japanese summers are tough to handle. Very hot and very humid. Be careful out there.
Todays idiom is "back to square one".
This means to go back to the beginning.
Example 1
I want to start a new business, so I looked at several franchises, but I couldn't find anything I was interested in. Now I'm back to square one.
Example 2
I had to go back to square one after spending days trying to solve a problem at work. It's so frustrating.