You were at the u.a camp for training. The league of villains attacked, and were trying to kidnap bakugo but they were also after you. Mr compress shot a ball out to try and catch him, when you jumped in front at the last second. They all left through the portal.

You soon woke up, finding yourself on a chair with a piece of metal that cuffed your hands together at the leagues base.

Shigaraki: So you’re awake? You got in the way of us catching bakugo..luckily for us, you were also a target.