古 The 古 sound set Mostly read コ See 古 as a kanji → These jōyō kanji all use 古 as a sound hint — a clue to pronunciation, not meaning. 故 コ happenstance, especially, intentionally 苦 ク suffering, trial, worry 固 コ harden, set, clot 居 キョ、コ reside, to be, exist 枯 コ wither, die, dry up ← All sound sets