I have no idea why this relatively new drama got such a high rating. It's one of the few that really annoyed me and got me angry even, - which is rather hard to accomplish. Here is why:

1. The male lead: So, who is this guy? He is supposed to be quite younger than the female lead, has just started his job more or less and he goes home into his house which obviously is in the most expensive area of the city, with probably 300 sqm, two story with galeria and a Zen garden outside, and which probably costs a silly fortune to rent let alone to buy. So how exactly does he get to have this house? Is he a Chaebol son born into immense riches? We don't get to know, he just has thta hyper fantastic home for the sake of it, - seriously?

2. So he falls in love with his female boss. Ok. But what he does is not ok. He has extreme stalking tendencies, immediately obsessive in a sick way for me. All of those rating this so high, could you do me the favour and just imagine for a moment that this guy does not look like Ro Woon but let's say he is a short, overweight creep guy with a balding head, greasy rest of hairs, yellow teeth and bad breath? Still so appealing that he keeps no distance, suddenly starts this ' I am very protective'-stuff, totally overstepping any personal boundaries, following the female lead around where ever she goes? Still fine, he aggressively steps into her private life and private relationships? Just think about it for a moment with a very different guy and if you'd still find this so lovely?

3.the female lead: Ah it's a pity really. I actually like Won Jin-A, she has a supercute look and face, a beautiful smile, a lovely deep speaking voice, I like all these things. Problem is, I don't think she is a very good actress. I saw her in three different dramas now and she is always acting the very same way, there is no variation - at all.
Secondly, she never has chemistry with the male leads. I know that most K-drama kisses are fake of course, but she makes it so fake it's hard to watch. She hardly ever moves her lips, or her head even, mostly looking scared and shocked like a rabbit in front of the slaughhterhouse. Why? And not only with the first kiss, it remains like that until the last episode. It's very obvious that she does not want to kiss the actors.

It was pretty much the same in 'just between lovers' - a bit better though, and it would have been the same in 'melting me softly' if Ji Chang Wook wouldn't have totally thrown her off guard which was rather obvious in that shower scene.
Here now we are supposed to believe she is a self confident modern woman on the one hand, having a secret ongoing affair with her boss and sleeping with him regularly for quite a while, and on the other hand she is not able to normally kiss thet new lover like an adult woman. Instead she acts like a 12-year old girl, anxiously not knowing what to do? What exactly did she do with her boss then all the time? A round of knitting together?
I do wonder why she would take on romantic roles if she has such obvious problems kissing her counterpart actors every single time? In this drama though there was no chemistry between her and Ro Woon AT ALL, it was just awful watching them.

4.. There is no backstory to the characters. I earlier mentioned the expensive house such young man owns without explanation. But also his character is like a flat sheet. Where does he come from? Why is he so obsessive on the one hand , and so totally unbelievably patient and almost asexual on the other hand? What else does he do in his life other than obsessing and following a woman? Does he have no other life? How creepy is that?

5. Totally unrealistic dialogues: again, the male lead acts like a saint without hormones or reproductive organs - no young man in his 20s would act like that, especially none who is so aggressively obsessive on the other hand. All this ' I will accept that you treat me like a trash bin, thank you, it's all ok for me as long as I can see you like this, and spend some time with you, or just look at you bla bla' and being all calm and smiles? No way!

6.The female lead is rather a unlikable person for me. She enjoys all the attention and treats both men like her puppets although it might look differently. I stopped watching when there was like the 50th scene with her then former lover. He for the 50th times asks her why she dumped him and she does not say why? Why does she not just tell him the reason? It really drove me crazy and made her character look weak and immature once again, totally contrasting to that self confident business woman thing the writers actually wanted to sell.

I gave up after 10 episodes because all this got me really angry, and I seriously do wonder how in 2021, they would produce such a badly written and acted drama with male and female leads going down the totally wrong road concerning many behaviours.
I was just thinking about that last real stalker case in South Korea some few months ago, where such obsessed sicko killed his former work colleague in a subway toilet room. I don't want to see this kind of stalking obsessive guys in K-dramas, not if t is nont shown in a critical way but instead selling this as desirable positive relationship. There is NOTHING to idealise or enjoy about this.