No actually Kihoon is the one who lost his memory, it'll be a long explain you may probably know this but I'll explain incase you don't know, actually when the rock was on it's sleep Lee yeon(ML) tied the res thread to kihoon in their past life to make up for that, in present life after all the tasks one of them must lose their memory, so Lee yeon chose to keep it and let Kihoon to forget abt everything abt lee Yeon.. that's it
No actually Kihoon is the one who lost his memory, it'll be a long explain you may probably know this but I'll explain incase you don't know, actually when the rock was on it's sleep Lee yeon(ML) tied the red thread to kihoon in their past life to make up for that, in present life after all the tasks one of them must lose their memory, so Lee yeon chose to keep it and let Kihoon to forget abt everything abt lee Yeon.. that's it

im confused could someone please explain what happened? did they both lose their memories