Ten or twenty years from now, this lakorn will be a classic and then it would be so appropriate when we speak of Pope/ Bella as Date/Kade, we referred to them as Kookwan.
Maybe someone Thai will explain “ kwan” but I think one term or context of it means “soul” so I would describe Kookwan as “soulmates” destined to be together. Another time I hear the term “ kwan” is when used in referring someone as your “ kwan chai” and in that context, it’s like “ ideal or dream” person ( of your heart). Like
@milquety said, it can't be translated with their full nuances.