so basically mom & daughter will do brain swap because daughter is terminally ill, but mom's brain will magically survive in daughter's body. I see 2 love triangle happening.
I didnt like ML's whole 'what if' & crying on beach. they broke up maybe more than decade ago. built life and family. if you are happy with what you have- you wouldn't cry like that, even if you needed closure.
I knew there were two possibilities- either she forgot him due to emotional trauma for losing all her loved ones or he wasn't 'chan' she was in love with (or maybe she fell in love with chan after chatting with ML & recieving pen as gift).