koto plectrum
A pick worn on the fingers to pluck the strings of a koto (Japanese zither).
琴爪をはめて琴を弾く。
I put on koto plectra and play the koto.
Compound of 琴 (koto, 'Japanese zither') and 爪 (tsume, 'claw; nail'), referring to the claw-like plectrum used to pluck the strings.