koto player vs instrumentalist

koto player and instrumentalist both are nouns.

Word	Noun	Adjective	Verb	Adverb
koto player	Yes	No	No	No
instrumentalist	Yes	No	No	No

As nouns, instrumentalist is a hypernym of koto player; that is, instrumentalist is a word with a broader meaning than koto player:

Other hypernyms of koto player include musician, player.

koto player (noun)	instrumentalist (noun)
a musician who plays the koto	someone who plays a music as a profession