To get to KITTE, exit the Marunouchi South Exit of JR Tokyo Station and head towards Yurakucho to your left. You'll see it soon enough!
Once you enter KITTE, go straight, passing the information counter, escalators, and BEER&SPICE on your way out.
Outside, in front of a cafe called Tokyo Lobby, there's a spacious terrace with seating areas.
There are stone benches that can accommodate around 30 people.
It's a relatively quiet environment, perfect for working on documents or taking calls related to job hunting.
It's also a convenient spot if you want to eat a boxed lunch near Tokyo Station.
As for the environment of the rest area, it's a spacious area filled with trees, so you can relax without feeling cramped.
Also, there are indoor "Sofa seats next to the KITTE escalator" nearby, so be sure to check them out too!
Why not use it as a place to take a break while shopping at KITTE or as a seating area around Tokyo Station?