簡
カン
simplicity, brevity
JLPT2 G6 S18 F983
間# gap + 竹 bamboo → collection of bamboo *slats* with gaps between them → *papers*; *letters*; *documents* (← texts written on bamboo slats) → *omit* (← gap) → *simple* (← simplify by omitting).
[Full Kanji Etymology List]