Youji Yagami is the father of protagonist Yūji Yagami and works as a salaryman. He shares an openly romantic and close relationship with his wife, Nomi Yagami, frequently displaying public affection towards her. These displays consistently cause embarrassment for their son, Yūji, especially when witnessed by Yūji's peers or teachers. Youji's family interactions form a recurring element of the series' dynamic, with his marital happiness contrasting Yūji's complicated feelings toward Nomi. Mitsuko Nanase, an office lady working under Youji, harbors romantic feelings for him and frequently attempts to flirt, though these advances do not appear to impact his relationship with Nomi. Throughout all story adaptations—including the manga, the three-episode OVA, and the eleven-episode television drama—his role centers on his identity as a devoted husband and father. His character consistently demonstrates obliviousness to external romantic attention directed toward either himself or his wife, focusing instead on his family life and career.