exclamation
欸 centers on an exclamation, a sudden vocal outburst expressing emotion or calling attention.
欸 combines 欠 (open mouth, breath) with 矣, which likely contributes the sound. Together they suggest a vocal exclamation.
The right side 欠 looks like a person with an open mouth, and the left side 矣 resembles a figure gesturing. Together they show someone exclaiming.
For アイ, imagine an exclamation of surprise: 'Ai!' The sound 'Ai' is the reading アイ, and the open-mouthed shape 欠 reinforces the outburst.
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