Presumably there is an English subtitle on the manga raw page or something that has the title Engrish like that is my guess.
On a sidenote: Is the phrase actually the romaji for Pioneer or is it maybe supposed to be a term more like Vanguard? If they don't specifically spell it out as パイヤニーヤ or such, I would do a bit of research into Japanese RPG/fantasy terms, because it's probably not meant to be translated literally.
As for comments of the series: MC suddenly acquiring a "daughteru" right away / slavery angle is an overused trope, but I'm curious where the story will go from here, as it doesn't seem like the focus will be entirely on the restaurant.