If this was a normal romcom for ladies instead of a yuri manga, Kan would totally be Miwa's fated love interest.
Rude, annoying, judgmental, thinks he's better than you, likes scolding you, likes explaining your flaws to everyone even when nobody asked him anything... the whole Tonoike Tazune package. It's always guys like that who are supposed to be good husband material. The leading lady's job is to mellow him out with her sunny cheerfulness and bring out the hidden tender & loving side of his heart... and, in fiction, it usually works like a charm. In reality, on the other hand, it tends to work more or less like it worked for Midori.
Thanks goodness this is a yuri manga and not a shoujo/josei romcom.