Hard pill so swallow: None of these characters have an actual personality. Yahwi is a short tempered moody "bad boy" and Cain is the bubbly sunshine golden retriever. In their own way both of them are obsessed with Jooin who is just as shallow/superficial as the other two. Literally none of the characters have hobbies and the only time we saw them outside of school or Jooin's home was when Cain and Jooin went on a date. It's not just Cain or just Yahwi who lacks real personality, it's all of them.
And the award for the worst dialogue and worst story telling of the year gooes toooo