介
カイ, すけ, ゆき
jammed in, shellfish, mediate, concern oneself with
JLPT2 G7 S4 F617
?a variant form of 人 person + an element# indicating two sides → person intervening to reduce/eliminate distance between separate parties → *intervene*; *mediate*. *Shellfish* is a borrowed meaning.
[Full Kanji Etymology List]