Tokyo is expensive, especially per sqft, but AIUI it has stayed about as expensive, modulo general inflation, since the 1980s. And if you don't have much money you have options like renting a tiny apartment that's a 15 minute walk from your 45 minute subway ride, in a neighborhood where you can probably walk or at least bike to a grocery story.
Meanwhile, cities like Boston and SF have tripled or worse in rent in the past 20 years. Downsized apartments without parking are banned by zoning codes, and living far out means you need to spend thousands of dollars on a car anyway.