Hmm...I don't know if Cain not telling Jooin about his family, who he currently has a dysfunctional relationship with, is more damaging than the emotional trauma Yahwi put him through with his actions behind the scenes between the two of them and in public in front of their classmates, but everyone is different. For some that could be on the same level, but I can only speak for how it would effect me.
I reread starting at chapter 30 and honestly no, he has not had a genuine moment with yahwi. Maybe in the first season when his crush started looking at him but 30 to 92 no. He started to distance himself from him around Ch.40. Only genuine moments I seen are with Cain esp the birthday and assumement park.
Listen, I'm Team Cain until the end...no ifs, ands, or buts. Yahwi was awful to Jooin the entire they were together. Correct if I'm wrong, but did Jooin ever have a genuine moment of happiness while with Yahwi? The story has been going on so long I honestly don't remember. Even if Jooin did a simple pros and cons list, Cain would win by 1000% percent. I'm starting to get like a lot of y'all and sick of this who will it be. This is literally why I stopped ages ago reading stories with 3 people on the cover because of a long line of "What is this BS" kept happening. I think this one was a leftover from that group and it will be my last.