Same as BJ alex where the first part of chasing arc was BJ alex asking the Uke if he wanted to be his fuck buddy again This is basicalky BJ alex 2.0 shifujo
But Kim Dan has extremely accute depression.
He has given up everything, he sees no light.
Everything that he loves leaves him, so he wants to numb the pain.
This could be a meeting point between Joo and Dan, they have different answers to being abandoned. (One feels irated, the other desolated)
At this point I can’t see a chasing arc. Watch him just find a way to blackmail dan or something