We did Tokyo disney and sea, they don’t close. Other places, you need to check carefully. The close before and after the new years.

Great. thank you!

Trains are actually the thing you don’t need to worry about as they actually run more frequently over new years. (Though, long distance trains like the Shinkansen are often packed and impossible to book the few days before and after New Year’s.)

As for tourist sites and restaurants, be sure to do your research! They often close over the holidays.