noun
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).
彼は外では厳しいが、家では内面がとても優しい。
He is strict outside, but at home his private demeanor is very gentle.
内面と外面のギャップが大きい人もいる。
Some people have a big gap between their public face and their face at home.