Technically the Japanese line says the box's purpose is "to purei", using the videogame-associated word for "play" whose Japanese pronunciation is obviously homophonous with "pray".

However, in English, it seemed a bit lacking that Akyuu and Keine would jump to the wrong conclusion from simply the word "play". Thus I figured that saying the box's purpose was "player", which outside of videogame terminology sounds like nonsense, would actually be a pretty good localization of the misunderstanding.