Responses
He says “mesu” in Japanese, which means female, but it’s a version of the word female that is usually used for animals. Hence using “Bitch” to convey that meaning.
Just remember that this is just a part of Renjaku’s character. But soon you all will learn to love him. Right now, he’s just being a tsundere.
PS. All this info and thoughts comes
In the spanish translation he said: he is my "hembra" that is like "female" or "my woman".
Still not appropriate but...it's quite better than bitch.