A story arc... I don't think we have enough people to properly do one. The only one that's still (relatively) active are the GM himself (daltar), zzzdragon, fillerdude, and me. As for Chariot and Clawthewolf... I'm not really sure.
The most obvious story arc will be an inter-school conflict (Umesaki against Yamashita), but engaging such arc will require solidarity between Burst Linkers of the same school, which requires a lot of building up remembering the current standing.
And from my personal experience, slow build-up is the thing that killed most roleplays out there.