ONE PIECE: PIRATE WARRIORS 4

The bronze and silver coins that you'll come across are littered throughout the maps. Bronze are obtained through capturing locations and defeating basic Strong enemies like Marine Captains or other faction-based leaders. Gold coins are a bit harder to come by, either by maxing their Crew Level or completing episodes in the Dramatic and Treasure Logs. Rare Silver, the last classification, is obtained in two ways as well: through reaching the repeatable Bonus level of Crew Level, or by chance when completing missions in the New World classification of the Treasure Log. You'll need to obtain 150 different coins to unlock Kizaru, so if you want to use that as a tracking feature, you could do that too.