
I read the web novel so this part maybe different from the light novel.
Momiji I believe was Benimaru's wife name. At least in the web novel it was required for Beni to get married and have offspring in order to complete his awakened demon lord evolution. Iirc it was because his evolution would cause him to become a spirit lifeform and he would no longer be able to reproduce but that was his job as the prince or king of the ogres. Also the fox was never mentioned in the web novel so yeah that's news to me.

I was plenty shocked about that when I was reading the novel. He was suddenly engaged and had to consummate (???) in order for him to enter evolution. And I remember just being glad that his marriage wasn't much on the grand scheme of things. So in the end, you can easily forget that he is now a mrried man. Lmfao
Ranga and the fox are in love!which is i am disappointed not only by ranga also by benimaru he marries to a girl :'( i dont like it at all(ofc everyone has his opinion) but i am really just wow i mean why... :( they should all stay single and serve rimuru anyways don't hate me for that just spoke about it (opinion as well)