While I could go for the low-hanging fruit and give Jana the same voice as Kuroki Tomoko (from Watamote, done by Kitta Izumi), Jana has that kind of crazy manic side of hers. I went instead with the voice of Hoshi Syoko done by Matsuda Satsumi. (I don't think the RPC can embed videos to start at a time so feel free to jump to 4:12.)
https://youtu.be/G4rqdfiKsqI?t=4m12s
https://youtu.be/G4rqdfiKsqI?t=4m12s