face shown at home; private demeanor
Refers to the relaxed, unguarded expression or attitude a person shows only to family or close companions, in contrast to their public face (外面).
He is strict outside, but at home his private demeanor is very gentle.
Some people have a big gap between their public face and their face at home.
Compound of 内 (uchi, 'inside, home') and 面 (tsura, 'face, surface'), literally 'inside face'.