To put things in perspective for Japan:
In all of history, 25 movies have made over $100M there. (Unadjusted gross in yen, converted at today's exchange rate).
9 have made over $150M.
2 have made over $200M. One of those is Titanic, at $256M. The other is Spirited Away, at $297M.
Unless you're predicting that it will do even more spectacularly well in Japan than anywhere else in the world, 100-150M should be the top of your range.