Currency Sakana is a linen bag of metal coins that allows for a variety of games with mechanics such as bidding dexterity and variable player powers.

In the first game "It's in the Bag" players will all start with a set number of yen bills and coins equaling 7500 yen. Players will always add one currency item to the bag (it is never allowed to make change) and then hold a blind bid for the contents. All bids are then placed to the side to be added to the bag for the next bidding round and the highest bidder takes all of the current yen in the bag. Play continues like this with players bidding on the last rounds bids plus one new currency item from each player until one player has 10000 yen or more and is declared the winner!