Shūji Takanashi is the father of Shūsuke Takanashi and husband of Nanaka Takanashi. He shares his son's perverted tendencies, demonstrated when he attempted to confiscate and keep one of Shūsuke's pornographic magazines for himself. This behavior aligns with his personal history, as he took Nanaka to a pornographic film on their first date. Nanaka consistently views their son as perverted, implying Shūji may have influenced or passed on these traits.