Yūki Izumi is a 25-year-old firefighter stationed at Sakuragaoka Fire Station, working alongside protagonist Souma Mizuno. Standing 187 cm tall, he has light olive hair, brown eyes, and a distinctive birthmark or mole. Izumi energizes his team as a cheerful mood maker who lightens the atmosphere. His primary hobby involves caring for his dog Sayaka. Throughout the narrative, he actively and consistently seeks a romantic partner, explicitly pursuing a girlfriend. Appearing in both seasons, Izumi maintains a secondary recurring role as a colleague and friend within the core group of firefighters.