Both characters take the heart radical 忄, signaling an inner emotional state. The well-known phrase 忸怩作态 means "to put on a coy, affected manner" — used disapprovingly of someone who acts falsely shy.
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Slightly literary; in everyday speech 害羞 ("shy") is more common. 忸怩 carries an extra nuance of being awkwardly self-conscious, often paired with body language like fidgeting or looking down.
