I dunno about western school, But back then in mine, classes were sorted by the order of the well scored and the flopped. So students who is good at last year's final test will go to early number class (for example: Grade 2 Class 1 or 2) and the lowest mark will go to the lower number class (Grade 2 class 7 or 8 or whichever lower).
Reason i bring this up is because this is pretty much how lower number class act like even with teachers around. And Keine's reaction is pretty much the same reaction any teachers get from them.
I dunno about western school, But back then in mine, classes were sorted by the order of the well scored and the flopped. So students who is good at last year's final test will go to early number class (for example: Grade 2 Class 1 or 2) and the lowest mark will go to the lower number class (Grade 2 class 7 or 8 or whichever lower).
Reason i bring this up is because this is pretty much how lower number class act like even with teachers around. And Keine's reaction is pretty much the same reaction any teachers get from them.
Judging from the moon, it's a waning gibbous, which is probably what Mystia and Kyouko mean in the commentary. There won't be any EX Keine for almost a whole month, so it's the best time to goof off! Any mischief will have had time to be forgiven or forgotten before next full moon.