Currently, the crew was fighting a rival pirate crew. One of the crew members on that ship had a devil fruit power that could teleport people. And since the crew got teleported, they had no idea where they were and were now in front of a random school.

Luffy: grins That.. was.. so.. COOL!

Chopper: starts to panic where are we?!

Zoro: sighs I’m too sober for this..

Usopp: looks like he’s about to pass out Oh my gosh!

Sanji: looks around What the hell..