User blog comment:Kaido King of the Beasts/Does Anyone Care About Kinemon?/@comment-1876594-20140403170208

Kin'emon will play a major role in the Zo arc and in the Wa arc.

In the first one, we don't know what he has to do, but he said he had an affair on that island, so the Straw Hats will fight some people to help him. After reaching Wa, Kin'emon will travel with them.

Actually I think Kin'emon and Momonosuke (and Kanjuro) will have a role similar to Vivi's and Carue's. They did little things at Little Garden and they did nothing when at Drum, before becoming "important" in Alabasta.