Primary

• Izaya Orihara Older Brother of Kururi Orihara
• Izaya Orihara Older Brother of Mairu Orihara
• Izaya Orihara In love with Shizuo Heiwajima

Extended

• Shizuo Heiwajima Older Brother of Kasuka Heiwajima
• Shizuo Heiwajima dislikes Izaya Orihara
• Shizuo Heiwajima Friend of Tom Tanaka
• Kururi Orihara Twin Sister of Mairu Orihara
• Kururi Orihara Younger Sister of Izaya Orihara
• Mairu Orihara Twin Sister of Kururi Orihara
• Mairu Orihara Younger Sister of Izaya Orihara