Miwa taking advantage of the other guy .... she doesn't even have to say she has a GF or disclosing her private life, she just have to tell the guy to back off, not gonna happen.
I guess you have forgotten about last chapter? At the party, this selfsame guy was yet again pestering Miwa with his advances, and Miwa showed him the finger and told him to go die in a hole. Pretty conclusive, right? But his reaction was to laugh it off while commenting "Ouch! Harsh but fair!" and now, one chapter later, he's at it again. This dude is thick like a plank, he just doesn't seem to understand the meaning of "Hell no!" and can't get a clue to save his life. It's not really Miwa's fault that he's so effing dense.
As for Kan, he's the worst chuunibyou character I've seen in a romantic comedy in a long time. Supercillious lone wolf act, always looking down on other people, only opens his mouth to tell everyone about their wrongs and mistakes... uugh. Guy needs to grow up and stop being a prick, fast.