THIS
Only reason Yahwi is the one with significant development is because he's the only one who truely needed it. Cain and Jooin don't need much as they're equal developed but do lack one thing each, with Jooin, as you said, he just lack conviction and Cain lacks communicate.
Idk how Cain is annoying yet Yawhi isn't? Both are quite possessive but at the same time they're not as Cain is willing let go unlike Yahwi who said he wants Jooin to want him even if Jooin gets hurt. Which shows despite his significant development, he still lacks development as he's still the same selfish guy as before.
I said Cain is annoying cause that’s his main trait, he’s a possessive person who can’t communicate and hurts Jooin, he’s also a little creepy(?) like he found Jooin in another country and manipulated Jooin into letting him live with him. I never liked him idk haha, but yea there’s a lot of space for him to grow. Yawhi is inherently aggressive and frustrating to follow as well. I just don’t see either of them as good love interests.
One of the best comments I've read so far!
Jooin actually establishes his boundaries and he has a firm attitude which is so different from other stories so I can appreciate that at the very least, but he has no conviction, he keeps running around in circles and it’s making him such a frustrating character to follow. Cain is so annoying and an obsessive dog who’s personality doesn’t change and Yawhi is a dangerous and maturing(?) sunbae, but the only one i believe is actually going thru significant character development. It’s still 0-3 for all main characters i fear