yes, what the fellas said, you need energy to enjoy it and perform well. also agree with belvaros, i've been around in diff countries and ginza is by far the best i've tried.
try book the girls earlier in the day (early afternoon), i have them either before lunch or few hours after lunch or before dinner (which is not possible for some people dep on schedule i know).
coffee also helps (for me anyway) if you're doing an early session. good luck and have fun!