i dont get hiw she gets a happy ending after she betrayed the mc lol

i meant to upvote sorry

its okay i understand

Wait I forgot, how does she betray her?

she and dawoon were best friends and then she left mc just because that creepy sunbae took a picture of dawoon with seontae. he spread rumors that they (dawoon and seontae) are going out so that blonde girl was mad because she was in love with him. actually dawoon was trying to help her, I think seontae ask her for help with gift or something like that?? yeah it might sound chaotic ╥﹏╥

Ahhhhh, I remember now. Thank you!