I liked the premise in the synopsis, but the way it actually plays out is 10x more ridiculous than the worst loser/nerd x gyaru story setups.
They go from people who had crushes on eachother when they were 12, to 30 year olds who immediately jump into bed together after meeting once, to getting married for...reasons? A one night stand after heavy drinking is the only part of this that makes sense, and its immediately ruined by the fact that they were both virgins before it and randomly decide they should marry eachother afterwards.
All of this works individually (childhood friends reconnecting, older and somewhat lonely people getting together, one night stand etc), but when its all smashed together it makes the dumbest and most convoluted start to a story i've seen in a while. I would have thought this was a seinen judging by the tags, but it doesnt read that way at all.
Its such an easy issue to fix too, if they'd just been exes or best friends with crushes on eachother up until university, but had grown apart because of her work as an idol, it would have worked so much better and been way more compelling as a setup. It would explain them jumping into bed with eachother and wanting to marry, rather than wanting to marry the person you had a crush on when you were 12 out of the blue.