Decide
Worth buying on a trip or not, settled one at a time against the official sources.
A Swiss pass: worth buying?
Moving between cities on consecutive days, take the Swiss Travel Pass. Based in Interlaken or Grindelwald for the mountains, take the Jungfrau Travel Pass. Travelling only now and then, take the Half Fare Card.
A Japan eSIM: worth choosing?
If you have an iPhone XS or later, or a Galaxy that supports eSIM, and want to keep your Korean number, an eSIM is the simplest choice. Install it before you fly and switch it on when you land.
Narita to Tokyo: Skyliner or N'EX
Staying near Ueno or Asakusa, take the Skyliner. Staying near Tokyo Station, Shibuya or Shinjuku, take the N'EX, which needs no change.
Tokyo Disney 1-Day Passport: which park
The 1-Day Passport is sold for a set date and a set park. Choose the park first, then buy once your date is fixed.
USJ Studio Pass: when to buy
Once your date is fixed, buy the Studio Pass in advance. It is sold for a set date and the price changes by date. The Express Pass, which shortens queues, is a separate decision.