5. Be My Favourite - multiple timelines, multiple variables but the only thing that never changes is the person you love. I absolutely loved the fact that it wasn't just a love story, the MCs character development and love story both grew independently without hingeing on each other like we usually see, but there's also no denying that the ML was definitely the MCs soulmate . There was angst, heartbreak and such an amazing love story that came out of it.
BONUS - Guardian (2018). Not an explicit romance, definitely not a clear ending, but their story.. it's just peak soulmates stuff