(srry for long comment)
(I have a theory that I have no idea if it's been confirmed to be canon or confirmed to be not canon and wanted to share)
So from what I get from this so far is Ther and Ronin were (assuming this is Ronin's backstory and taking place before Killer Chat) together. There is something i noticed though. Angel and Ther both have blue eyes, the same voice actor, and are both Ronin's ex. So they could be the same person just different times? I know some people change their names sometimes. (I haven't finished Angel's route in Killer Chat though so I don't fully know)