In a Japanese couple I know, he refers to her as Kaa-chan,  Calling her
"mother" even though they DON'T have children.

Keiichi Masaki wrote:

I know that "anata" is the accepted way for a woman to refer to her
lover or husband, but is there any particular way or word that a man
would use to his wife? Also, would the use of "-chan" fit this catagory?

Help would be appreciated...