“plain” is definitely a choice to describing someone kind comforting sweet and loveable
Jo is the plot development. Without him the plot would've stayed the same. It's very telling when Jamie (the villain of the story) had to wait for years to finally make a move against Ian, TJ and the gang. He also knows that Ian isn't someone that will get close to anyone other than TJ. Now since he knows Jo exist, he will use Jo and Chris as a bait to go against them. I think his grand plan will has to do something with Jo. I think most of you guys and Jo himself have presumed that there's nothing more to himself than what he is known for which is not true. There's more to him than meets the eye. His character development will finally start when his darkness will consume him. In simple when he actually meet Jamie. Meeting Ian and falling in love with him will be the biggest turning point in his life because he will get to know his real self. I hope you don't call a bad dude when gets dark.
Ian needs to get his shit together, ヽ(`Д´)ﾉ he's giving mixed signals, I know that TJ is important to him cause he was "family" after him telling TJ that they need to break up but I more confuse about the existence of Jo in this plot. There's nothing on Jo he's just so plain hayssss