That part is similar, but the plot is not at all the same. I mean in kill me heal me, the girl was abused by her father and the boy saw it happening and got DID. In this one the only one who got hurt is the boy, and the black haired helped him. So no, they are not similar in the parts which make up the plot.
We don't have much to go on with this plot but idk about you those flashbacks seem to hint at the DID guy being abused as a kid and meeting the MC. which is extremely like Kill Me Heal Me. It will probably be a little different but man this idea definitely came from somewhere.
God look at the Male lead. Just put some glasses on Cha Do Hyun and he's basically the Male lead here. I'm not saying this is absolute trash or anything just that we can see where it originated from
Guyyys theres no need to argue. DID is a pretty specific theme with reacurring tropes and story beats such as child alters and girl alters doing something shocking which the mc reacts to. plus DID is almost always brought on by trauma so abuse is an easy cause for stories. Obviously this manga is not the exact same as the drama but the author might have been inspired by it or even wanted to retell a similar premise. I just commented cus when rei became a girl and ran i thought of the same scene in kmhm so i thought it was hilarious. Yall opinions are all valid (⌒▽⌒)
Big Kill me Heal me vibes if anyones seen that kdrama