Three days in Tokyo is tight, but it's enough to see the city properly if you plan by geography instead of by bucket list. The mistake most people make is bouncing between neighbourhoods on opposite sides of the city, spending half the trip underground on the metro. This itinerary pairs adjacent areas together so each day flows naturally on foot, with short train hops between the pairs.
You'll cover six neighbourhoods across three days: the traditional east side (Asakusa), the neon-lit west (Shibuya and Harajuku), the gardens and nightlife of Shinjuku, and the food and art corridor running from Tsukiji through Roppongi. It's a full trip. You'll walk 10-14 km per day, but Tokyo has a way of making that feel effortless because there's something to eat or gawk at every fifty metres.
Before you start, pick up a Suica or Pasmo IC card at any train station (load it with about ¥3,000). It works on every train, bus, and convenience store in the city. Google Maps handles all the train routing perfectly. And bring cash. Plenty of the best ramen shops and street food stalls still don't take cards.
If you have more time, our 5-day Tokyo itinerary adds teamLab Planets, Odaiba, and a choose-your-own-adventure day.