But why stop at golf? If we can put a driving range and a putting green in the basement, why not a fishing stream? Why not a shooting range? A running track with facilities for pole vaulting and throwing a miniature javelin?
Tokyo has reformed the game of soccer so it can be played on a field as big as a tennis court. We call this game "fusbol" and it is very popular in Brazil. Perfect for the basement.
We could certainly engage in rock climbing in the basement. Not on a mountain, but on a cantilevered wall with intricate handholds and if desired a strong crosswind and flashes of lightning to add a touch of color.
Sailing as we know it would not be possible in a basement, but tacking back and forth through a slalom course on a sailboat as large as an ironing board seems a possibility. It wouldn't be the same as sailing off Kamakura, but it could be technically challenging. And skiing down a slalom course, with the course rolling up continuously on an escalator.
Similarly auto racing, where the point would be not how to handle sheer speed, because the course would be only fifty meters long, but cornering with millimeter accuracy.
Could we schedule wars in the basement? A pocket war would allow opposing armies (no more than a dozen soldiers on each side) to perfect their tactics and work out aggressive feelings, while keeping damage within bounds. After the final battle and the armistice, the opposing armies could enjoy a beer together before catching the subway home.
Such basement amusements might seem unreal to foreigners, but in Tokyo it seems perfectly natural to think this way.