Kidnapper

Because The One is to large to go to Hocotate and Koppai, she found someone to kidnap the three and Olimar. Small hints about who he is is given throughout the game, but his name is not given until the end, after you beet The One.

Plot
The kiddnaper is really Louie.After the events of Pikmin 3, the koppaits had left him on PNF-404 by mistake. He had only lived because of The One, and so he helps her whenever needed; which is why he kiddnaped the three and Olimar.