I know a few of them which I will list here :
My top fav it’s Scarlet heart ryeo where the 4rth prince it’s obsessed with the female lead and this one it’s a sad one . Get your tissues when you start this . Prepare emotionally!
Another one is missing you . I also cried with this one too. I love the 2nd male lead more .
Another one is secret. Ahh the actor it’s amazing in every drama he plays on . I love his every drama but this one it’s with him obsessed with the “killer” of his girlfriend. It’s a must watch too.
Another which I’m currently watching and how can I never see anyone talking about it . I have been watching many dramas lately but during watching dramas of Jang Ki-yong I came across BORN AGAIN . It’s really an underrated drama . I should have know this . Here also has the guy obsessed with the female lead on the last life and the new life too. He stalks her everywhere and does everything to save her even though he puts her in danger unintentionally. I pity him .
Another one is bridal mask . The 2nd lead is obsessed with the girl . This one is an old drama .
And the last one is the red sleeve . The crown prince soon to be king is too in love with the girl which is a maid of the king . He is obsessed to have her all to himself even though she doesn’t want to be king’s woman because she wants to have freedom . Also this one is similar to scarlet heart ryeo so bring tissues if u want to watch it .
I hope I can find more of this type of dramas . If someone know please reply to this message. Happy watching .