I see, he used the "treat her like shit, then treat her like a fiance" tactic - works like a charm on any generic shoujo main character.
Still don't know how I feel about how she's deciding these things. Not only has she gone to Tokyo to postpone her marriage with handsome-kun by ~3 years (leaving him by himself for 3 years before finally breaking up with him), but she's left her best friend who likes the guy with no way of being around him. No weasel -> no way for handsome-kun and best friend to meet on an occasional basis. She's abandoned her friend's love life in order to destroy her own in a roundabout way.