This is a Kabuki dramatic dance from about 5 centuries after the time Unkei worked However, it is deeply influenced by Japanese Buddhism in its plot and dramatic form.
(Don't worry, there is a very good English narration to help you follow the story).
That's the last of the rarified and refined Japanese aesthetic for now.
Be warned that I love this stuff.
The PreRaphaelites are going to look very maudlin after all this.