Last week, I got to read a secret chapter 23, and it turns out "Orie" is actually short for "Murder on the Orient Express" and "Shuuichi" (Hayasaka's first name) is a reference to Shuuichi Saihara from hit vidya game Danganronpa V3. Their parents really liked murder mystery stories. In fact, they even named their third child "Huntington Hayasaka" (早坂半珍問) after famed anti-romance mystery writer Willard Huntington "S.S. Van Dine" Wright. (Though the canonicity of this "chapter 23" is highly debated.)