Apparently the vps' voice characters in D4DJ but the voice banks themselves are based on their Utaite personas it seems.
The D4DJ connection is interesting, for those not in the know, it's another mobile rhythm game by Bushiroad like Bandori, but focused on DJ groups instead. (As far as I understand, full disclosure I am not a D4DJ player.) The banks do not seem to be developed under the Bushiroad umbrella but I wonder if the creators got involved with Dreamtonics through Bushi. That would make sense imho.
Anyway, they look interesting, Nakuru is my vibe design wise but I am not sure how to feel about the voice (it's not bad by a long shot I am just not vibing with it for some reason). Itsuki both has a cute voice and design but I feel exsisting VB's already well cover her niche, including the upcoming PASTEL and HALO, voices I am actually interested in.
But it's always nice to have more folks throw their hat in the vocalsynth ring so I'm not gonna complain. But yeah my first impression so far is lukewarm to optimistic? I imagine fans of them will be happy, they seem to be decently popular Utaite if the youtube numbers are anything to go by. Edit: Also I find it fascinating that whereas Nakuru's desing seems to be an inverse of the vp's utaite avatar in terms of style and colors Itsuki is more like an approximation of the avatar's desing/vibes but with enought flourishes to make it feel different. The Musical Isotope/Yumenokeshou school of vsynth design vs the V3 era aproach of "Separate character that is still the VP's 'sona' in spirit".