Alright, the author is just taking the piss at this point.

My current theory is that the author and his assistants (or maybe just his assistants and he quit bothering long ago) have a great big die with story tropes on each face and as necessary, they just roll the die and do whatever it says.

Since they finished the “sports festival arc,” they had ro roll the die again, and it came up “study group.”

And here we are.