Your first day in Tokyo after a 12-plus hour flight is not the day to attempt a packed itinerary, no matter how excited you are. I've watched too many friends burn out on day one trying to see everything. Here's how to actually spend those first 24 hours so you land on your feet instead of crashing on day three.
LANDING AND GETTING INTO THE CITY
From Narita, the fastest way into central Tokyo is the Narita Express (N'EX) or the Keisei Skyliner, both around 40 to 60 minutes depending on your destination. From Haneda, you're much closer - the monorail or Keikyu line gets you into the city in 20 to 30 minutes. Buy an IC card (Suica or Pasmo, physical or on your phone) at the airport before you leave; it saves you from fumbling with ticket machines while jet-lagged. Resist the urge to power through and hit a major sightseeing spot on the way to your hotel - drop your bags first.
THE JET LAG PROBLEM
Flying from the US or Europe puts you 13 to 17 hours off, and the single best thing you can do on arrival day is get outside into daylight rather than napping the afternoon away. A short nap of 20 to 30 minutes is fine if you're desperate, but a long nap will wreck your sleep schedule for days. Aim to stay awake until at least 9pm local time, then let yourself crash hard. Melatonin an hour before bed on the first two nights helps more than most people expect.
WHAT TO ACTUALLY DO ON DAY ONE
Keep it low-effort and walkable. A slow wander through Asakusa and Senso-ji temple is ideal - it's atmospheric, doesn't require much planning, and the surrounding streets have enough food stalls and shops to keep you occupied without a rigid schedule. Alternatively, a walk through Shinjuku Gyoen (a large, peaceful park) is a good antidote to jet lag brain - green space, benches, and no pressure to "do" anything. Save Shibuya, Harajuku, and anything requiring reservations for day two or three, once your energy is back.
WHERE TO EAT WHEN YOU'RE TOO TIRED TO DECIDE
Don't overthink meals on day one. A department store basement food hall (depachika) is perfect - point at what looks good, no menu-reading required, and you can eat while walking or find a bench. A conveyor belt sushi spot is another easy, low-decision-fatigue option. Skip anything that requires a reservation or a long wait on day one; save the bucket-list restaurant for later in the trip when you're not running on four hours of plane sleep.
MY TAKE
The biggest mistake first-timers make is trying to "make the most" of day one by cramming in three neighborhoods and a rooftop bar. You'll enjoy the trip more if you treat day one as a soft landing - one neighborhood, one simple meal, and early to bed. Tokyo isn't going anywhere, and you'll actually remember day two through ten a lot more clearly if you don't start the trip exhausted.