zhēn​miàn​mù

true identity

真面目 zhēn​miàn​mù
true identity adjective
the actual appearance, character, or original state of a person or thing, often as revealed after being hidden

The swindler's true colors were finally revealed.

Frequency

Movie subtitles
4.23 per million appears in 2% of films
Written text
2.28 per million

Sources

Definitions
CC-CEDICT