Er, I wouldn't go that far. Saying a grappling line and a kusarigama are the same thing because they have chains and you swing them is like saying a hammer and an axe are the same thing because they have handles and you hit things with them.
Well, regardless, the weapon Mikey used later in the Fred Wolf version was actually a a type of kusari, or at least it was called that.
The -gama part actually refers to the kama (sickle) attachment. So the full name of Mikey's old alternate weapon would be manriki-gusari kaginawa (ten thousand power chain with grappling hook).