idk why it never occurred to me before but I just realised that Yujin, who grew up neglected by his dad (and his mum passed away early too iirc?), is ironically best friends with Jingrui, who grew up with love and attention from two mums and two dads.
(granted, Xie Yu is very much Not A Good Dad and didn’t give Jingrui much love but most likely at least did not neglect him)
I think that the fact that Yujin still turned out to be a good kid has a lot to do with his friendship with Jingrui but I also wonder if they got into fights over this… like Jingrui was under intense pressure to live up to the expectations of both set of parents while feeling like he didn’t belong anywhere so he might sometimes be jealous of Yujin, while Yujin probably wished that his dad expected more of him than ‘spend money’.
maybe they bond over feeling like they don’t belong to any of their families and maybe that’s why they like to go off gallivanting in the jianghu because there are probably tons of stories about orphans or family black sheeps who find their place in the world and form everlasting bonds of ~true friendship~ through their adventures in the jianghu.