Tokyo as a city offers some great food, e.g. in form of sushi and yakiniku barbecues, great onsens (Japanese natural hot spring baths), and some great parks especially during the cherry blossom season.
Also, if you have more time to spend, you can easily take a day trip to either Mt Fuji or if visibility is limited to the much nearer Mt. Takao as I did.
Getting around Tokyo is super simple as the train and metro system is really efficient and covers the entire city. But be prepared you wont be there alone: if you’re not used big city traffic you may want to avoid rush hours when people are in practice pushed inside the train cars.