Loudlout- kun's feed

and here i was just thinking if there was a manga where the couple is already established coz i am bored of slow burns and never ending hate to love tropes. what luck to come across this manga! and the beautiful art is a plus. i can't wait to read more. oh and anyone know of other manga or manhwa where the couple is already established? i couldn't think of anything else but tadaima, okaeri