The Noh play, it turns out, is really hard to understand. As best you can tell, the samurai's wife is really mad because all the samurai does is sit around playing MarioKart, and so she commits seppuku. Then he swears revenge (although it's unclear why) and goes off to kill his daimyo. In the final confrontation, the daimyo loses his katana and thus cannot defend himself. Uh oh ! What do you do?

Watch the conclusion of the play, secure in the knowledge that it's not real.

Be an idiot and jump on stage to defend the daimyo because you can't tell fantasy from reality.