If you're going to be a ninja, you've got to look the part.
Although I'm not sure real ninjas have purple and gold toenails.
Or stalk squirrels with their cats.
But if they work really hard (and just show up for their second class) they are awarded their first belt: white. I'm not sure if he's truly over wanting to be a police officer or if this is just a diversion. It'll be fun to see where this goes.