front and back; inside and out; two sides; duality (often implying inconsistency or inseparability)

💡 Nuance & Usage: Often used to describe something having two contrasting aspects, like appearance vs. reality, or public vs. private behavior. It can imply hypocrisy or a close, inseparable relationship (as in 表裏一体). 表と裏の二つの側面を指し、言動の不一致や、密接な関係性（表裏一体）を表す際によく使われます。