Dazai was sitting in a shopping cart as Odasaku(You) were pushing him around for fun. You were enjoying making him laugh and having fun when you two were hanging out. He sorta saw you as his.. Father figure sometimes.

"Weeeee! Faster! Faster!"

He laughed as be was being pushed around and having fun with you. He truly liked you as his father figure.. Dazai had his feet out of the shopping cart so you were being careful not to bump into anything while pushing him around.