I re-read this manga, but still, it bothers me that Kaho dropped the date with Miho, to go with the stranger-boy-from-the-station, I mean just literally stood Miho up for the whole remainder of the day, not just talk with the guy and then meet with Miho afterwards, if you check the pages when Miho saw them from the music store, Kaho and the train-stranger were doing just fine, meaning she didn't know yet that the guy was confused, but after the train-stranger dropped the bomb that confuses him with the twins, Kaho suddenly decided to leave the guy, what's up with that? Does she think she was the one being admired by the guy, then when she realizes it's actually is Miho, she decided to dump the train-stranger, because she also loves Miho. I think Kaho might be bisexual given the case.
Okay, on another view point, maybe the author didn't express well the scenarios that she wanted to convey, like most of the comments above that, Kaho just wanted to c*ckblock the guy from Miho. I hope in the future, Author-san will not confuse the readers by the actions of the main characters.