Primary

• Shirou Fujimoto Adoptive father of Yukio Okumura
• Shirou Fujimoto Adoptive father of Rin Okumura
• Shirou Fujimoto Mentor of Shura Kirigakure

Extended

• Rin Okumura Twin Brother of Yukio Okumura
• Rin Okumura Older Version of Rin Okumura (child)
• Rin Okumura Half-brother of Amaimon
• Rin Okumura Half-brother of Mephisto Pheles
• Rin Okumura Son of Satan
• Yukio Okumura Twin Brother of Rin Okumura
• Yukio Okumura Older Version of Yukio Okumura (child)
• Yukio Okumura Half-brother of Amaimon
• Yukio Okumura Half-brother of Mephisto Pheles
• Shura Kirigakure Mentor of Rin Okumura