a tale of 4 moons

in which y/n narates a story (to her adopted daughter choi yerim) of boy lived in her past who was a termianlly ill patient named beomgyu also In which beomgyu a terminally ill patient creates a world that doesnt exist with people he loves so dearly.when the times comes how will he be able to let them go and find himself before its to late. And will doctor y/n be able to help fill beomgyus empty heart or will her heart be scared with muted feelings she could never express.