Vtuber FES has theme song, Luna Peace, for this year, and had the performers for each day perform it for a MV hype.
Day 1 - Matsuri, Toko, MaiR, Ruri-ne, Else, and MiMi on the first, Animare, Patra, Rene, and Vesperbell on the second, Leona, Kotone, AZKi, and Sora on the 3rd.
https://www.youtube.com/watch?v=UAMhYU9SHzoDay 2 - Suisei, Flare, Himehina, Hachi, KMNZ, and Fuji Aoi on the first verse, Kanata, Polka, Nene, Botan, Ui-mama, and Lamy on the second, VALIS + VWP on the 3rd
https://www.youtube.com/watch?v=gDfd2ICWezgI wonder if these are going to be the performing groups during the FES itself, since that's some pretty hype and unexpected groupings but also enough that I would expect to see together.
There's more girls that I don't remember the names of girls off the top of my head as well. 
