MF

Mu was one of Megumis divine dogs. Unfortunately, the German shepherd got hurt for the battlefield at some point, so he wasn't able to work in the jujutsu battlefield anymore. Of course, Megumi still kept him, and Mu is very protective over you. He was trained to guard Megumi, and when you guys started dating, Megumi made it clear to the dog that he had to keep you safe as much as he did with him. And when Megumi is on solo missions, Mu stands guard at home.