You can't do Tokyo in 24 hours, you are going to miss many of the "do-not-miss" anyways. So you will have to make choices. First thing to realize is that Tokyo

You can't do Tokyo in 24 hours, you are going to miss many of the "do-not-miss" anyways. So you will have to make choices. First thing to realize is that Tokyo is not really a single city but a prefecture, it is like a bunch of smaller cities (wards) stuck together, and there are 23 of them. They all more or less independent and they have their own center, and they also have some kind of theme. All that to say that there is no "downtown Tokyo", and choosing what to do in Tokyo is essentially about the districts you will choose to visit. Which one depends on your interests. Shinjuku which is a major business center at day and a shady (but still safe!) place at night, Shibuya for fashion and youth, Roppongi for foreigners and its nightlife, Asakusa for its temple, Yoyogi's park, Akihabara "Otaku" mekka, Odaiba's futuristic vibe, Ikebukuro's shopping centers and arcades, Ginza's luxury, etc... Tokyo-Edo museum is indeed awesome if you are interesting in the history of the city, and it certainly a "do-not-miss", but on a 24-hours stay, you have to make choices. If I had to pick one to add to any list, maybe Shibuya crossing. It is one of the most famous sights of Tokyo and a symbol of the busy city it is. It is also right out of the station on the Yamanote line, so close to other notable places. Just north is Harajuku, Yoyogi, and Shinjuku, all worthwhile.