The Poko is the currency used on Olimar's home planet, Hocotate. Pokos were officially introduced in Pikmin 2 as an important part of the plot. Olimar and Louie are tasked with obtaining × 10,000 to repay Hocotate Freight's debt, which is made possible by selling treasures and enemy corpses found by the two explorers while on the planet of the Pikmin. In comparison, × 100 is more than a year's wage for a Hocotatian. Pokos are oval-shaped, thin, and made of some sort of golden colored material.
Throughout their adventure, Olimar and his partner can task Pikmin to pick up and carry treasures into the Hocotate ship or the Research Pod. When a treasure is successfully recovered, it is analyzed by the ship, and is given a value in Pokos. In the overworld areas, recovered treasures are added to the Poko count instantly, and enemy corpses can only be delivered to the Onions to increase Pikmin population. But in caves, enemies can be brought to the Research Pod to exchange for a small amount of Pokos, and any amount of money gathered while inside a cave will only be added to the total if the cave is exited via a geyser. Otherwise, the collected objects are left behind in order to allow the Pikmin and leaders to escape.
Although not related to the game's story, Pokos also play a role in Pikmin 2's Challenge Mode, as part of the scoring system. Despite Pokos never being mentioned by name in Pikmin 3, the game's Collect Treasure! stages have a point counter at the top of the screen that shows an icon quite similar to that of a Poko.
Mentions of Pokos
Hocotate money is mentioned at some points in the first two games. When the final ship part in Pikmin is recovered, the Secret Safe, Olimar states that it is as full as ever, meaning none of his Pokos were lost. Some pieces of mail in Pikmin 2 allude to Pokos too: