Senso-ji Temple in Asakusa is the classic first stop, and the surrounding Nakamise shopping street is worth a slow walk even if you're not buying anything. Shibuya Crossing is one of those things that sounds silly on paper β just watching people cross a street β but it's genuinely worth seeing at least once. The Tsukiji Outer Market still has some of the city's best seafood breakfast spots, even though the main wholesale market moved to Toyosu.
Akihabara rewards fans of electronics and anime with a genuinely dense concentration of shops, while a day trip out to Hakone or Nikko offers hot springs, mountains and a break from the city if you have the time. Booking a slot to see the observation deck at TeamLab Planets or a similar digital art installation is worth doing in advance, since the popular ones sell out.