limp, staggering gait, embarrass
尬 centers on an awkward physical or social state: a limping, staggering walk, or the embarrassment that comes from being in an uncomfortable situation.
尬 combines 尢 (a person with bent or weak legs) with 介, which likely contributes a sound element. The character suggests a physical unsteadiness that extends to social awkwardness.
The outer 尢 looks like a person with uneven legs, and inside 介 suggests being caught in between. Picture someone trying to walk but stumbling, feeling embarrassed as others watch.
For カイ, imagine a person with a limp trying to walk along a winding path that looks like the letter K, and they sigh 'Kai...' in frustration: Kai -> カイ.