Hello! I have a question!
What is Kawaakari vibes in your tag?
Hello! Thank you for asking, because this gives me a perfect excuse to go on a special interest info-dump. :)
Though, I will balance that with not turning this answer into something that's the length of a novel.
Ahem, anyway. One of the things I really enjoy doing is watching chorus battles. I won't really go into what those are here-otherwise, this really will become novel-length. But the point is, I've been watching as an invisible/silent spectator for years, but I'm a bit more involved now. Sometimes, I even write fanfictions for entries that I have particularly enjoyed or been intrigued by, or whatever.
Anyway, one such chorus battle (or CB for short) is called Kawaakari Academy Chorus Battle (KACB or KACB2 for short). It's actually had/having two iterations. One is ongoing now (it's in its registration period, where groups sign up to take part) and the other one started late 2020 and finished in the summer last year. I'll refer to that as "last year's Kawaakari" for the rest of this answer. One of the interesting things about KACB/KACB2 is that it is very, very story-rich. So it particularly captured my imagination and interest above and beyond the general interest I have in watching CBs.
So, with last year's Kawaakari, I found myself thinking about what the world in which Kawaakari Academy existed was like, and writing a number of fanfics as a result of this. KACB essentially became my special interest within a special interest. As a result, I would sometimes find that I'd come across posts here that reminded me of certain aspects of Kawaakari Academy, which is what made me like them. Sometimes, I'd even look out for posts that had a 'Kawaakari' kind of feel to me, just to reblog them. Hence me using the tag '#Kawaakari vibes', because that's what the tag communicates: that there is something about the post that reminds me of Kawaakari. Whether that was something in the canon (so to speak) or just something that fit with my own headcanons and imaginings of what the Kawaakari world was like, to me those things had those vibes.
HOWEVER, though I have been doing that for a while, initially I started using a different tag. That tag was #Luciform vibes, named for one of the fanfictions I wrote for last year's Kawaakari. That was a multi-chapter affair, incorporating entries from multiple participating groups across all three rounds. It is one of the fanfics I am most proud of from a writing perspective, though I am slowly making minor revisions to some chapters. But I digress. Some of the things I re-blogged and tagged with the "#Luciform vibes" tag were all things that could fit a more general "#Kawaakari vibes" feel, however some things reminded/remind me specifically of certain plot aspects of Luciform. So while last year's Kawaakari was ongoing, and while I was still writing Luciform, I mostly used "#Luciform vibes" but after both were finished I gradually switched over to "#Kawaakari vibes".
I have a feeling I will be using the tag a lot more now that this year's Kawaakari is under way. I am participating in a group this year, as their storywriter (which is quite a privilege, as usually teams don't go for seperate story-writing members, the main categories of team members are vocals, mix, art and animation). But even if I wasn't I would be ready to immerse myself into whatever new lore is given this year. I would possibly even consider writing more fanfic, though since I'm a participant for now I wouldn't commit to a huge thing like last year's Luciform. Even with that though, as I said, Kawaakari Academy has become a special interest within a special interest, so I would still end up coming across things that remind me of it.
Anyway, that should answer your question.