Hayate Murazumi

Hayate Murazumi, also under the alias Sadakazu Kojiri, is a major character and the older brother of Aika Loveglade.

He was known as the Ultimate Pulmonologist before his arrest for the murders of Nozomi Nakano and Kaede Toudou, subsequently resulting in his expulsion.

Personality
Through what little the viewer gets of Hayate, he appears to be a very protective older brother figure. He is very hotheaded and aggressive, proven through his conversations with Kaede and Seiko, and will go to drastic measures to achieve his goals. His sister is his closest loved one, and he is willing to protect her at the cost of his own life.

Despite his short temper, Hayate is also quite calculated and intelligent, especially in his murder plans. However, his emotional nature exposes him as a criminal very easily.