I thought ahjusshi meant uncle thats y it felt awkward .. either way it’s probably cuz I am used to seeing “hyung” rather than just “mister” アニメ♥
"hyung" is a more close form... And here he literally goes for "Ahjusshi" and which sometimes translates to Mister but also to uncle as well so I can understand why you got confused lop
The dialogue was so cringe omg “mister”