I wonder if the pun works in both languages
The kids are on a field trip but also need to walk into a field so yeah it works in English.
I don't know japanese but 遠足 translates to "excursion" and is made up of the characters for "far, estranged, temporarily long" and "foot". I'm guessing it's not a pun based on how the kanji is read, but on the meaning of the word itself just like in English.