Everyone knows that Steven never went to real school like us but what if he was forced to go to a REAL SCHOOL?
Connie's teacher find Connie playing with Steven and ask him if he went to school, Steven says no. The teacher is forcing Steven to attend the school but CGs didn't like the idea and willing to convince Connie's teacher of not let Steven attend the school because his power is too much for human beings.
I can see Pearl like 'K-KINDERGARTEN???' and Amethyst like 'There aren't kids in the Kindergarten, dude.' and Garnet like 'Actually, there are. And it looks different...' But she was actually using her future vision on a classroom then they go to the Kindergarten and Garnet is panicking in her mind when she thinks her future vision is off. Maybe it's the Kindergarten Kid and maybe Steven's education takes place there now XD