Tokyo looks expensive from the outside because it is full of premium food, big-name attractions, and efficient transit that makes it easy to spend money quickly. But the city also has a deep free layer that most first-time visitors never fully use: forested shrine grounds, riverside parks, old market streets, and station-to-station neighborhoods where the best experience is simply walking. If you plan the day right, you can see a huge amount of Tokyo without buying a ticket. If your broader trip budget is tight, this sits nicely alongside How to Travel Japan on a Budget: Cheap Eats, Transport & Stays.
The trick is not chasing "free" as a gimmick. The trick is understanding how Tokyo actually works. A shrine visit is best early in the morning. A market walk is best when vendors are open but the lunch crowd has not fully arrived. A park works best when it is treated as part of a larger neighborhood loop, not a random stop. That is the difference between a bare-bones day and a genuinely good one.