So, maybe people with experience of Tokyo winds can share: how bad can it be?
In general, my approach to this trip is to avoid jetlag by living more or less on Swiss time. The contests start at 6:00 Zurich time, which is definitely early, but not outrageously so. Given that I'm here for just 4 days, it seems logical to not bother shifting the schedule by much, and to sleep 20:00-5:00 Swiss time (=3:00-12:00 here).
One of the benefits is that I get to do sightseeing in the evening, when it is much more pleasant outside, and there are less people everywhere. The flip side of this coin is that many places will be closed at night.
One particularly important challenge is getting food. Lunch happens during dinner time here, so it is not really an issue. I will be late for the hotel breakfast, but it will already be lunchtime, which means that I can get some lunch food in one of the cafes near the Shinjuku station (not sure if the lunch in the hotel restaurants will be quick enough to be in time for the contests). However, what to do about dinner? Any suggestions about where to eat in Tokyo at 1am? Bonus points if your suggestion comes in the next 2 hours ;)