From Wikipedia:
"The K10W1 was not popular with crews possibly due to ongoing handling problems and only served with a small number of units which included the Oi, Go, Takarazuka and 81st Kokutais (Naval Air Groups) as trainers. Japanese records do not show that any were used for Kamikaze attacks, although a small number were definitely used as target tugs for gunnery training and as unit hacks attached to operational bases where they probably assisted in getting new pilots up to speed."
That's the entire operational history on the Wikipedia article about it. Seems like the K10W isn't a good fit for IL-2