Actually, that's not how you're supposed to use a Kusari-gama. The recommended technique is to use the chain to entangle the foe, and then finish them off with the sickle.
@EasyModo: What exactly did he do, though? Just swung the blade of it by the chain?
I've heard of an actual discipline known as Houten Ryu in which it's used that way. Then again, though, I'm comparing apples to oranges since Houten Ryu supposedly uses a modified kusarigama as opposed to the usual.