"Who are you"? Muku asked in a threatening voice the moment he landed, startling the group of strangers standing in front of the girls.
His dangerous aura was leaking out a bit. It was almost like he was indirectly telling them that if he didn't like their reply, they were going to suffer.
"Hey! You're scaring them!" Emily spoke as she hit Muku on the shoulder.
She hit him as a way of showing the spooked strangers that he wasn't as unreasonable as he seemed at that moment. Of course, there was a little rebuking involved as well.
She had noticed long ago that he did particularly like it when males, especially strangers talked to them. While he wouldn't react like that in normal cases. Jade's annoyed voice when she called out, made him misunderstand the situation.
She, in reality, only spoke in such a tone because of their quarrel. However, in the heat of the moment, such a possibility slipped his mind. His prejudice got the better of him.