he sounds like a lot of fun so far and they can definitely know one another through the younger brother. i'm not sure what you have in mind personality wise for the sib but it could be they became close friends when ismael initially moved there around 11. him being the older brother, i wonder if he wound up with them harshing those "dark boy" vibes when he was stuck with them? if no that's okay! ismael can be painfully awkward but has his own brand of personal weird that he lets fly in close company, so they might be able to riff after each other there. he'd definitely support his online company and feature the merch by wearing it on a moderately popular ig he runs!