>>88917415I think it might be half and half. Take the Holo GTA arc for instance; I'm guessing some of the girls sat down before and after streams to discuss some fun story ideas like the bakery cartel's love triangle or La+'s confession to Towa, but that (maybe) most of it was improv and happenstance.
Running jokes like Subaru yelling KANADE were probably one off bits that worked really well on the audience so they kept playing it up for the laughs. However I think other moments like Kronii's dine-and-dash fugitive arc just happened organically.
