Who pays Japanese / Australian wedding

My Australian son is to marry a Japanese girl whose family will travel to Australia for the wedding. Who should pay for what?

The couple should pay for the ceremony and reception. Parents should offer monetary gifts, but how much is up to them. The Japanese parents will probably give a substantial amount, but according to Japanese tradition, the woman marries into the groom's family. So the groom's side is expected to also be very generous.

I am from NZ and married to a Japanese guy- we got married in a third country, and we paid for the ceremony etc by ourselves, as well as for my mother-in-law's flight because she is past retirement age and not working. My parents paid for their own flights and accommodation.

I am from the US and my wife is Japanese. Our situation is a little different from yours, as we had 2 weddings, but here's some things that I learned during the process.

We paid for our Japanese wedding. The cost was largely covered by wedding gifts (which is money in Japan).

For our US wedding (which was quite a bit cheaper), we split the cost with my parents and again much of our portion was covered by wedding gifts since as we are living in Japan most people gave us money.

Things to consider:

I am told by my wife that in Japan the grooms parents may pay for the wedding, or if split then the grooms parents would pick up a larger percentage of the costs. That may or may not be after factoring in gift money. But of course, every situation is different.

If the couple will be contributing, you may want to consider that the gift money that the couple receives from friends and relatives in Japan as being part of the brides family's contribution, since the money is essentially reciprocal gifts that their family gave or will give to those friends' and relatives' children when they get married. This is a point that my wife made when we were getting married.