Bangkok
The best street food on the planet, and a transport system that makes the chaos navigable.
The most rewarding big city on earth for people who like to wander.
Tokyo doesn't have a centre so much as a dozen of them, each with its own personality — and the trains between them run so reliably that a day can hold four neighbourhoods without feeling rushed. It's enormous, immaculate, and far easier to navigate than first-timers expect.
It's also the best food city in the world at every price point. A ¥900 bowl of ramen from a vending-machine counter can outclass a tasting menu somewhere else. Plan loosely, follow your nose, and accept that you'll only see a fraction.
Cherry blossom and autumn colour are genuinely worth planning around, and both come with mild, dry walking weather.
A workable shape rather than a schedule to obey — two fixed things a day, and room to change your mind.
Get a Suica or Pasmo on your phone and stop thinking about it. The Yamanote loop connects most of what you'll want; Google Maps handles transfers accurately down to the platform exit.
Tokyo rewards splitting up. Restaurants seat parties of two to four easily and groups of eight barely at all, so plan to break apart for meals and meet at a station. A shared plan with everyone's picks on it saves the endless 'where are you now' texting.