She may flip out over really silly things. Like if you have a tattoo and she just finds out. I know someone who was going through all this with the MIL. Then the MIL found she had a tattoo. She canceled the wedding plans.
I know enough about Japan's culture to do something like get a tattoo or such. Plus, many of my Japanese friends say I think like a Japanese person. I'm a people person. If someone asks me for a favor I will not turn them down. I like people to be happy, even if it means sacrificing my own happiness (until some jerk named ryuurui posts on my forum, see below - of course I will say things to complete strangers on the internet that I would not dare voice face-to-face). Anyway, my soon to be in-laws are all very sweet and wonderful, and if I did anything to offend them, I would do my best to remedy the situation. They have already done so much for my family and me, that I couldn't even imagine having a better family to marry into. Love them. Not too worried.
What the heck?! First, you only know 1 happily married internationally mixed couple – you must not know very many people. I, on the other hand, know plenty, and all seem to be doing pretty damn well. (excuse my French) In fact, just 3 of the couples I know have been happily married for probably between 20-30-ish years now, not to mention plenty of others who have been married within the past 10. Second of all, you don't know my fianc・or me very well. Not all of us are so narrow-minded and culturally ignorant that our marriage will fall apart.
One thing I have found in the 6 years I have known this man is most of our disagreements and miscommunications can be blamed on cultural differences. Usually once we figure this out we laugh about it and come up with a compromise. So don't you dare tell me "心からお悔やみ申し上げます" and say that's what I should expect. That tells me nothing. A person that does her research, seeks the advice of strangers, and the help of her friends wants her relationship to survive, and to avoid making the same mistakes such as the ignorant fools that you happen to know.
If you must ask why I don't just stick with asking people I know... they're all in the opposite situation and live in the states. I would much rather ask them than have to deal with jerks like you. If you reply to this forum with nonsense again I will find a way to block you, remove your posts, or something along those lines. I only want useful comments. I don't care if they hurt my feelings or if it's something I don't want to hear, but I don't need any negativity.
Thank you, and go have fun raining on someone else's parade because I for one will not put up with this kind of BS. さようなら.
Get off this, guys. She wants to know what to expect as far as the ceremony is concerned, not her life afterward.
Gentlemen, let's please focus on the OP's questions and not further derail this thread. Thank you.
Thank you, and thank you.

Sorry for such a long message, but I seem to be in the worst of moods today, and this is a great place to take out my frustrations, rather than in real life.
On a side note, sorry if anything I wrote makes absolutely no sense. Allergies are kicking my butt. Ugh... >.<