Primary

• Hiyori Tono Best friend of Ikuya Kirishima

Extended

• Ikuya Kirishima Younger brother of Natsuya Kirishima
• Ikuya Kirishima Former teammate of Asahi Shiina
• Ikuya Kirishima Former teammate of Haruka Nanase
• Ikuya Kirishima Former teammate of Makoto Tachibana
• Ikuya Kirishima Best friend of Hiyori Tono