It's all subjective. For me, I just wasn't convinced in Jojo's reasoning for leaving SunOh and choosing HyeYeong. The explanation she gave didn't add up with her own recollection of how things went down in Season 1.
She tells SunOh in Season 2 that her reason is; "when you first came to our school, all I could think about was HyeYeong." WHATTT? When he first came to their school, she was dating some other dude and didn't know HyeYeong existed until meeting him in the nurses office (At least that's what she says was the first time they met). If she truly liked HyeYeong before all that, coulda fooled me! I mean they even worked together and she didn't bat an eye in his direction.
I'm all for growing up and maturing in love and making your own choice. But Jojo didn't really do any of that. Well to her credit, she tried to make her own choice by downloading the shield, but I don't believe it was because secretly all this time she was in love with HyeYeong.
Something was missing in this season 2 story telling, that I think made many people feel lost and unable to connect with the characters. I mean we literally had to have DukGo come back to life and explain it all to us in the last episode, because Jojo wasn't understanding it all herself along with the rest of us.
I'm just over here waiting here for Jojo's friend and Leather jacket guy, to show me their journal notes to each other, because I'd watch that instead.