Miyabi - defacto leader and the Tokino Sora of Holostars, used to be in a horrible state because of the constant shunning by holofans but 3D and post-concert momentum helped him gain his confidence back, his charm is that he practically had a contrasting personality despite how he looks like (his Hanasaki forest hijinks and fanboying over sexy girls in games) and it doesn't feel out of place somehow
Izuru - see above
Arurandeisu - does a lot of work for his mengen content and kaigai-friendly streams, king of hlst shitposter, had a bit of a setback from his fanbase after the sudden model change and the rumor around it but has been calming down for a while now
Rikka - one of the early faces of holostars before Roberu took over due to his aggressive collab reach, easily one of the best singer due to his background and is basically a male roboco down to his pon antics, though to me he hasn't got anything going lately after releasing his new song
Temma - the appointed project leader of the gang, Astel often talks about none of his genmates are sane people and it's very apparent in Temma as the dude likes to do things out of a spur moment. He recently made
Visual Novel-like stuff that he showcased on his birthday stream, he commissioned the necessary pictures and work the rest himself down to scripting and programming the VN. Most branch-wide collab like wordwolf, marika tournament etc. are usually organized by him
Roberu - non-holostars fans probably know him the most if not the only hlst they knew. Really great at the things he's good at and overall very fun to watch in every kind of stream that people don't mind his singing voice being mid as hell
Astel - His fps-antics are his 2nd strong point, I actually like his singing voice the most out of all starsJP and the dude always try to make sure he put out the best show during his 3D live. My main worry is that he's extremely menhera and would likely be the first person to drop out if cover no longer lets him do his project in peace
Shien - most of his mengen content is very fangirls-oriented because he's good at giving fanservice, he's the kind of dude who borderline into fudanshi which is why he has more notable female fans compared to everyone else. He's particularly good at voice acting though so it contributes to why he had certain views of the type of content he likes to do
Oga - very diverse content, in terms of watchers he had the perfect 50:50 split of male/female fans and is generally not afraid of initiating conversation with the girls. Though he's extremely introverted in the sense that he rarely drags people to do collab and rarely reaches out to people outside of the holopro bubble except a select few (He also never once interacts with fellow vtubers who share the same illustrator as he is, even has stated that he's unlikely to be in contact with the njen boys), which is a shame since he always came up with fun ideas during collabs like the recent omotenashi from hell ones.