Today's lesson is at the school's pool. Yokoi-san takes it very seriously, while Seki-kun messes around with his friends... and it appears that some familiar robots are back...
This is the worst time to 
be fooling around.
Gerade jetzt solltest 
du doch mal ernst sein.
c’est pourtant le cours
où il ne faut pas s’amuser.
Questa non è proprio l'occasione
per scherzare.
Isto não é hora de ficar de joguinho.