My perception of the popularity of the Aqours girls based on fans:
(Was gonna do a ranking but honestly I don’t even know how I would accurately judge them so Im gonna avoid putting rankings)
Ruby: Seems popular, but not actually that popular. Probably popular in Japan at least but not much outside perhaps??
Hanamaru: Good amount of people are for Maru, how can you not love a cinnamon roll like her??
Yoshiko: Up there in popularity, a great stand out character that has a lot going for her. Potential to be the best or worst character in Aqours (but she’s gonna be good dont lie haha).
You: Most popular girl for sure, can’t really escape that fact if you follow Aqours for a day or two.
Chika: Either loved or neglected, but I think thanks to her being more fleshed out in the manga and just a better design than Honoka over all, she’ll be a more popular Protagonist.
Riko: Conserved middle of the pack safe choice. Not stupidly popular but how could you dislike another cinnamon roll?
Dia: Very much biased here since she’s my best Aqours girl, but seems like a good portion of people like her too. I think it’s more of the fans outside of Japan though, but who knows?
Kanan: DAN KANAN UR KAN KANS ( ͡° ͜ʖ ͡°) Really though, seems like she was bland to people at the start but I think she’s picking up steam in popularity. Im sure people like her for the wrong perverted reason though >.>
Mari: The forgotten one, I hardly see anything Mari related anywhere. I think she’s been under represented in most of the Aqours media though, so hopefully they’ll give us more Mari in the future so we can get a feel for her full character.