Honestly, the art and the story itself isn't bad. The way it's all worded though isn't the best. I'm also not a fan of the whole roommate trying to get with Julie, maybe if Julie's roommate tried getting with the MC then made the same deal Julie and Ahn made then it'd make sense.. But her trying to kiss Julie so soon after meeting just doesn't sit right.. Another thing I'd like to make a point on is Julie "loves" him but they hadn't even had their first kiss after confessing. That just doesn't make sense to me.
They have kissed. Even on the slowest route possible. And on the other two routes they had sex. Not sure how you missed that.
As far as Alex kissing Julie goes. It was a heat of the moment thing. She doesn't even know MC, yet. Aside from his name and that he has something to do with Julie being sad. She did realize that she made a mistake and says as much. Apologized more than once for it.