This is an IDOL unit which means they need girls that can both sing and dance. All three girls can do that. I hope Nene will be the center because she can dance really well. They already have their own Twitter.
https://twitter.com/NEGI_U_official?s=09Suisei and Watame won't do these because they want to focus on solo gigs. Sora and Azki have their own music labels.
This can be the first of many sub units. Towa, Flare, Mel, Aki, Polka and Kanata are the only girls I think that will be able to perform and dance average choreo while singing. Average means more than swaying while standing in place. Maybe Miko and Marine too.