I’ll be very honest and straightforward. If you dig Rowoon (and who can blame you?), watch it for him whilst switching off your brain and not paying attention to the story or the bad acting that surrounds him.

Nothing extraordinary or original. Unnecessary filler scenes that were they absent, they wouldn’t alter the plot or deprive the viewer of vital info (but serve as a cf, so I guess they make sense?).
The drama is a cacophony of cliches. E.g. why, oh why, is the FL always gullible when it comes to bad relationships but assertive in her job? (I’ll take a hard guess and say due to severe insecurity?) Such poor representation of women all round.

Oh, did I mention bad acting? Won Jin Ah plays so stiffly the role of the senior (sunbae) and is generally.. old. Then she has a partial lobotomy and warms up a bit but still, she’s an old maid trapped in a body of a supposedly 30 yr old. Naturally, not much chemistry going on, therefore, making it very hard to root for the OTP.
No character stands out apart from the fact that they’re all pretty weird. Even Rowoon’s niece. It’s hard to feel the emotional bonds between any of them.

Just small examples of bad writing, directing and shall I say unfortunate costumier choices too? Were they all deliberate in order to make a point?
To finish it would be a Herculean task. Need I say more?

3/10