While Tokyo is a big city, if you stay in Ginza, Hibiya, or near Tokyo Station, you are within walking distance of so many cool things to see:
Gardens, parks and Imperial Palace.
Funky architecture in Ginza.
More traditional architecture with Kabuki theater and shrines and temples in the area.
Pokemon Center DX if that is in your wheelhouse.
Even the underground shopping arcade in Tokyo Station is something to behold.
Just tell us what types of things you are interested in and we can load you up with suggestions. A few months back I managed to fit in an anime pop-up exhibit, a trip to a convenience store (more fun than it sounds), and time to shop at the Pokemon Center and Tokyo Station in a
7-hour layover. I wouldn't recommend you do that, but the point is that you can cram a lot into 24 hours!