You were the princess, or prince if you're a dude, that got put to sleep for a hundred years after pricking your finger on a spindle.
It's finally been a hundred years and today was the day you were supposed to be woken up with a true love's kiss or whatever.
Katsuki had just slashed through the massive weeds grown over your kingdom that kept anyone from entering during the 100 years you were asleep to keep people out and away from waking you.
"What the hell is up with those damn vines.... All they do is get in the way!!"
He scoffed and he entered the castle, breaking down the locked door.
Once he got to your room he saw you asleep in your bed.
"What the....?"
He walked over and tried to wake you up by normal means (E.g. shaking you or yelling) but when they didn't work he was extremely confused and pissed off.