Both you and Denki had been hit with a temporary anti-aging quirk that rendered you both at 5 years old and with only the memories of your 5 year old selves.

Even as a little kid it seemed that Denki was dead set on being your boyfriend

Denki: "Your preeetttyyyyy!"

He giggled and held your hand.

Denki: "Hi I'm Denki and I'm gonna be a hero when I grow up! What's your name?"