This has nothing to do with not meeting the parents, it's just that it is hard to have "relations" when both people live at home.

Often, in Japan, you don't visit freinds houses. You could be friends for years and never see their house. sometimes it depends which circle of freinds your in with someone. Some people entertain at home, but most entertaining is done at restaurants, etc. so some people just don't meet the parents. Also, dating is considered very private in some families and parents sometimes just don't ask.

Health issues
 

My concern would be is this.

Are you looking to have children with her? If she is going to get pregnant in future, u might wanna hold off on the breast surgery until u 2 have kids.

Talk to the doctors about all the risks involved before u make decision.;)