Yeah he's in yandere love with Duroa. And right now her friends lives depend on how well he can reign in his urge to murder every obstacle between them and lock her in his mansion forever.
Or you know if she just got married to him for reals.
I feel like this was a massive waste of time and everything was super unsatisfying.
My family background actually is polygamous (my grandpa had 5 wives) and let me tell you polygamy works fine as long as the wives don't live in the same house and you don't necessarily marry for romantic love...