亲密无间 (qīn mì wú jiān) — on very intimate terms; extremely close and without any distance

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

This origin belongs to the traditional form 親; 亲 is its simplified writing.

The traditional form 親 uses 見 (see) for sense and 辛 (a chisel) for sound; the simplified 亲 is a shorthand and its parts are not the historical components.

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

密 pairs 山 (mountain) with 宓 (mì), which gives the pronunciation, to picture something hidden in the mountains, hence secret.

A drawing of the thing itself, worn down over three thousand years into a few strokes.

This origin belongs to the traditional form 無; 无 is its simplified writing.

For the simplified 无, the story is about 無. 無 drew a person dancing with ox tails held in both hands to pray for rain, then was borrowed for 'have no', so the picture does not explain that meaning.

No reliable origin is recorded for this character.