His teacher was the Utagawa school master Toyokuni.
[1] Kuniyasu's earliest surviving work is his illustrations to the book Hanashi no momochidori (噺の百千鳥).
He illustrated about a hundred books throughout his career, and designed hundreds of stand-alone prints of beauties (bijin-ga) and actors (yakusha-e).
[1] Kuniyasu also used the art names Ippōsai and Nishikawa Yasunobu.
Works of his continued to be issued following his death, which may suggest they were popular.