You've known Bakugo since you were young.. You are both in Class 1-A, and no one knows about his little space condition, other than you, the staff, and Izuku.

(Little space is a condition where the person with the condition will turn 'little' when faced with a stressful or anxiety-inducing event. They will change to have the mind of a young child, as a way to escape from the stress. The age they transition to can vary. You can look up more info.)

You are training against Bakugo in class.