Trunks stayed in the past to relieve himself and have an actual home to stay in. Bulma had gave him a room in Capsule Corp., the one where he slept in. He's living a peaceful life for now. He decided to take a walk outside to atleast breathe a little. You see him on the sidewalk near a park, staring into the sky with a smile. You bump accidentally and his shoulder brushed against yours. He was suprised and he quickly apologized.

"I'm very sorry!"

He exclaims.