Pretty sure that's an electric shamisen, not a banjo
I do just want to say I love how much Yuugiri seems to just roll with this whole "being awoken a century in the future and being forced to use technology she has no understanding of" thing. Pushed up on a stage with zero preparation? Well, let's just pull out a fan and start a fan dance. Oh, wait, we're doing a rap battle, instead? OK, let's just pull out a shamisen and put down some beats that are somehow actually appropriate to the situation, somehow.
She probably would have been alive for cameras, trains, electricity, and the earliest form of movies to be introduced, but she's a straight-up geisha used to sexually servicing customers after entertaining them with music and dancing for half a night just down with being shipped in a van to do "lives" in front of "fans" where selling your perceived untouchability and chastity is the key marketing strategy.
When everyone else is in front of a PC is one of the first times she even talks about it, and she pretty much just says "I've decided to just go along with whatever everyone else is doing because I gave up on understanding what the fuck is going on."
