Primary

• Eru Chitanda Friend of Houtarou Oreki
• Eru Chitanda Friend of Mayaka Ibara
• Eru Chitanda Friend of Satoshi Fukube
• Eru Chitanda Friend of Kaho Juumonji

Extended

• Satoshi Fukube Boyfriend of Mayaka Ibara
• Mayaka Ibara Girlfriend of Satoshi Fukube