In addition to Wakana seemingly seducing Akira after rejecting Osako's idea before, she also seems to have arranged a double date after deciding not to push an Akira-Imani relationship. Unless Rika is just hanging out offscreen?
Idk, this seems like a very strange way to deal with your suicidally depressed sex addict friend.
Wakana is reported by Osako to be led randomly by her obsessions, and that is why (in her mind) she has to fear Wakana so much, cause one day she can simply be led by something that does not agree with Osako anymore.
That is simply untrue in the case of their relationship, but it has an inkling of truth in that Wakana does not know how to deal with her obsessions - said obsession being Akira. There is the Sekai stuff, yes - but their connection existed before that and was instant, like super chemistry.
Wakana was very pissed Akira didn't visit her at the hospital, she invited him to her home at her relationship's anniversary, she took him to a date at the first place she took Osako to, she led Osako to the bathroom while flirting with Akira - then she became obsessed with him even more because it overlapped with her research into Sekai.
What I mean to say is that Wakana is not in control when it comes to Akira, whereas she is fully in control when it comes to Osako and everything else in her life. I don't mean Akira is in control either, Wakana definitely calls the shots between the two of them, but she isn't in control in terms of what she "decides" to do. Her scene when he comes back to school makes that clear, she slaps and hugs and has a breakdown before managing to put herself together again. And while understandable, this is not the only time she does that, it's just the other times are more subtle.
Like, she didn't have to call him to her home during her anniversary, she didn't have to take him to such a special place in order to ask for forgiveness, she didn't have to "joke" around seducing after the others told her to kiss him, or saying that she'd have sex with him to have sex with Niki. But she engages in that behavior whenever there is a "reason" for it aka whenever she can justify it to herself.
Akira means a LOT to her, and there is a subconscious Wakana that makes her behave unlike regular Wakana when things have to do with him (which we like to call: she has the hots for him but she is faithful to her relationship). The thing Osako gets wrong is that Wakana is an adult, and while she may veer off from what would be the safest for her (simply moving away from him) she simply wouldn't ever act on it if Osako wasn't hellbent on ruining their relationship.
That's my interpretation at least. So yeah, Wakana will take every opportunity to be with Akira that can be justifiable in her mind (in this case either forcing him to take some time off, or "friend jealousy"), but I think it's the same old "I care more about you than I should and I'll create a way to show that" (that's acceptable for a "married" woman), even though I don't think she realises she's doing it.
Edit: also, if any of them touch on the Sekai stuff I swear to god, I'm throwing hands.