k, I can do that.  Keep in mind I haven’t actually played the game, so I’m going off of what other people have said and sheer memory (this was, after all, a year ago).  So I think it goes something like this:

The Sakura story and Asagi story parallel each other, then the Asuka story happens.  Kiryuu, the scientist from Taimanin Murasaki, has been captured by the Taimanin and has spent the previous six years or so removing the alterations done to the girls from the initial games.

Sakura and Murasaki are investigating the sex trafficking thing and get captured and thrown in a rape room.  I think this triggers Asagi’s launch into action.

Asagi is director of the Taimanin and she’s have a secret affair with the younger male character as the first part of her story.  He has the special ability to make women lust after him with some type of chemical rose thing.  He’s not using this for evil, but he’s conflicted about it.  Asagi doesn’t seem to mind apparently, since I think he’s the brother or something of her fiancee.  I think he gets turned into a meatball monster (which is left unresolved at the end of the game).  She actually gets pregnant by him and has to have an abortion because if she doesn’t Oboro and Black will use the fetus against her, manipulating the demonic energies within her.

Asagi is captured and run through Oboro’s ringer of tortures and stuff, which has several paths and non-canon endings.  In one, Sakura and Murasaki are corrupted, fuck her, then have her turn the Taimanin school into a school for training the girls as demon prostitutes.  That storyline could also end with Asagi being forced to kill the two corrupted Taimanins.

Ultimately, the ending with Asagi where she’s finally broken by Black is the correct path, I think.  Because that leads to Asuka’s story…I think.

Asuka is being forced into sexual situations by some pawns of Oboro and a threat of violence against people she cares about.  The bad ending for her is she’s turned into a sex slave.  The good ending is she kills the people attempting to control her and she’s pitted against the falsely turned Asagi in the arena, who she thinks has turned and betrayed the Taimanin, but not really of course.  She possibly kills Oboro with some missiles, then she and Asagi team up to finally and completely destroy Edwin Black.

Ingrid’s story is a side story.  She and Oboro hate each other, they’re basically enemies but Black keeps them from killing each other.  Of course, Oboro being the more sadistic one, she’s able to capture and overwhelm Ingrid and bring her to the mind/body altering room.  She corrupts and turns Ingrid, using her to manipulate Black while making her a sex slave.  Ingrid’s fate is actually left unresolved at the end of the game.

The masked Taimanin that’s in a few scenes is actually the original Oboro.  The Oboro that’s been in all the games is actually several clones of that original Oboro.  She’s been working with the Americans and wears a mask to hide her identify.  In the end, I believe her being killed by Black is canon, which is kind of a shame.

I think that’s everything, poorly related, and filled with unanswered questions, but it’s the best I got at this current point in time.