>>37400869I'll give my opinion on this
Towa: quite close to Suisei, is the only holo she meets quite a bit for yakiniku dates, has gone to Towa's house a few times, Suisei is quite comfortable inviting herself to Towa's house and they met during her long break while on surgery rest (along with other holos). Suisei relies on her when it comes to stuff like tech issues, and this I don't know myself but apparently Towa relies on Suisei when she has menhera outbursts. Since they were part of startend for vsaikyou they spent an insane amount of time together offstream where they got to get to know each other even more.
Miko: collabs with Suisei a lot, they have gone out to eat together, went to USJ with shiraken, talk a lot during shiraken long calls, have talked offstream just the 2 of them while on call, Miko is the holo Suisei banters with the most, they support each other a lot on their individual projects, such as Miko appearing 6 times on Suisei's radio, Suisei is the only person Miko reached out when feeling down during the undokai preps, they seem to grow closer and closer over time. Overall they don't seem to hang out offstream a lot, as least not as much as Suisei and Towa, but this is to be expected since Towa is rather extroverted while Miko by her own admission never leaves her house. Still, they seem very comfortable with each other and Miko throws a fact or two about Suisei on occasion which shows their closeness. Suisei also told KoroAzu about how to make Miko feel at ease around her which seems to come from experience.
Aqua: gets harassed by Suityan, spent a lot of time together during vsaikyou practice, grew closer this year due to that, recently Aqua is rather more playful around Suisei which the latter noticed and said it's a sign Aqua is growing attached to her (delusion?).
Basically it's between Towa and Miko, the 2 are by far the closest friends Suisei has in holo, what I listed are moments that gave both girls the opportunities to get to know Suisei and viceversa. I'd say either can win the Suibowl but I hope it's Mikoti of course.
