ユースミルス・C・R・ウィンタテリウム

"...The walls and floor are cold here. Perfect for sleeping." Rufen's first-class roommate. His expression is always blank and he's constantly sleepy. Communication with him is difficult because conversations with him are always brief, lack explanation, and don't last long. He seems to think a lot of things, but it's hard to tell what he's thinking from a glance. He always complains about being hungry or tired. Somehow, he seems to be popular within the school...? [Translated from official website]