Basically Sejin and kwon were married and all misunderstandings and stuff happened which ruined Sejin life and eventually he commited sucide and then kwon killed himself as well. But then the past reset and they got to redo the whole marriage and thing again where Sejin forgot what happened but kwon remembered. So kwon made sure everything stay good for Sejin till the last point where kwon also cancelled the engagement so Sejin can have better life. Sejin who didn't have memory came to cry at kwon that he is abandoning him. The heated argument let kwon to mark(bond) with Sejin which basically triggered Sejin memory of other timeline and his death.
After this Sejin decided to leave( basically marry my husband also have same concept)
Idk…like I understand but I am not understanding what is actually going on.
Basically Sejin and kwon were married and all misunderstandings and stuff happened which ruined Sejin life and eventually he commited sucide and then kwon killed himself as well. But then the past reset and they got to redo the whole marriage and thing again where Sejin forgot what happened but kwon remembered. So kwon made sure everything stay good for Sejin till the last point where kwon also cancelled the engagement so Sejin can have better life. Sejin who didn't have memory came to cry at kwon that he is abandoning him. The heated argument let kwon to mark(bond) with Sejin which basically triggered Sejin memory of other timeline and his death.
After this Sejin decided to leave( basically marry my husband also have same concept)