Alternateens is a prequel to SHION that takes place in 2003. There isn't a cohearsive storyline compared to Shion as there are multiple main characters in it with different perspectives and stories. The main characters are Sheena [punk], Alison [grunge], Mall Emo [no name yet], Gabe [metal, specifically nu metal], Trad Goth [no name yet], young Avery and young Gabbie. A lot of characters, I know. They are all the main characters in their own respective scenes but they all hang out with each other as well.
So Sheena would mainly hang out with the punks in her own scene and there would be stories based off of that. However those punks wouldn't be as close with other genres as Sheena is. Hope that all makes sence!!