It's just my interpretation:
They're were lovers in past life, and in this life they met in they're school years. Something must happened between them and the other guy seems to don't remember assistant (sorry, I'm very bad at remembering names), but maybe in future chapters they expend this topic, so we know what that part was all about.
Now this two are adults and very much strangers (even if assistant looks like he remember the other guy when they passed each other on streets), but I assume that's just begining for second couple plot and there wasn't showed to much to not give away too much answers at the beginning.
Ooih that makes sense, thank you!! I was really confused, i thought they already have their story somewhere i didn't know, and the part of the fight was super weird and ugh. I hope the author expand their story
Help i didn't understand the story of the assistant ?