Yo! That was sweet!
I'm guessing you don't even have a story line?
Ok here's what I was thinking:
The three people you see singing are thieves. They live in the subs and occasionally venture to the main city when they're low on cash. However, recently they stole something very big and important. The man in the red cloak with the weird ninja-star sword is trying to hunt down the person who stole it. He's some kind of spiritual hero who works for the emperor. The man with no jaw is his prime suspect, but he actually didn't steal it. However, he wants it just as much as (if not more than) the man in the red cloak.
if you think this is a good idea then PM me and I'll tell you the conclusion... don't want to add a big spoiler here if you know what I mean.