Remember that in the last chapter she literally tied her up?
As she proceed to first just wipe her. And that's hardly just BDSM.
intercourse without given consent, a.k.a: rape
Intercourse ? Didn't she just suck her nipple one time ? And she barely smooch her breast here. Does that really count as intercourse ? Sexual assault yes but not rape.
I mean... you're technically right, but like, does it matter? They're both deplorable actions. And Hayami probably would've escalated it to rape if Akane hadn't freed herself anyway--at least she says she wanted to.
I'm not sure this distinction matters much outside of a courtroom.
Words, both inside and outside courtrooms, have defined meanings. Granted, the meaning of words can change over time, but we should respect the current meaning of a word and use it in the proper context. This is important if one wants to convey their thoughts to another and not be misunderstood.
For example: My understanding of chapter 3 is that Hayami physically restrained Akane, and committed sexual assault with intent to rape.
Again, you're technically correct, but do you see how pedantic this distinction is here? People colloquially use "rape" and "sexual assault" in the same way literally all the time.
Like, when you say "they were raped", the most important thing you take away from that information is "they didn't give consent", not "there was penetration". Who cares if there was penetration? Their consent shouldn't have been violated regardless. At a certain point the details about what exactly happened don't matter, and by saying "well it wasn't technically rape" it sounds like you're sorta letting the perpetrator off the hook. Like, "wait just a minute, it wasn't as bad as rape, they were only sexually assaulted". Who are you to decide that? It's not so simple.
Who cares if you call a fictional sexual assault rape. It really doesn't matter.