Japanese couples "anniversary" q-n?? XD?

Question:

I was wondering how do Japanese couples celebrate on their anniversaries and what kind of anniversaries do they actually have??
Like a 50 days anniversary, 100 days anniversary and etc??
And what do they actually do on these days??

PS:I am asking about Japanese couples LIVING in Japan. :) thanks

Answer:

It depends on each couple. There is no general answer.