Pikmin 3 puts you into the shoes of three intrepid space aliens from the planet Koppai — Alph, Charlie and Brittany, who have been tasked to save their food-starved citizens by bringing back edible botanical specimens to repopulate their planet.
However, the ship develops mechanical trouble and crash lands on their target planet, which they call PNF-404 and looks suspiciously like our own.
The three explorers get separated, and starting with Alph, have to reunite and complete their mission.
The only problem is that the Koppai are very small compared to the animals and terrain of PNF-404, making it difficult and dangerous for the explorers to navigate the world without help.
Luckily, Alph soon discovers that there are other mysterious alien creatures on the planet which he calls Pikmin.
These cute little Pikmin soon prove to be very useful because they can reproduce so rapidly and come in so many varieties that you can build an army to help carry items or fight enemies.