Detective Kyosuke Kozu's Murder Reasoning 8 (1988)

President Ito, a major apparel maker, was poisoned in the president's office. Kenzo (Baku Ohwada), who happened to be interviewing nearby, rushes to the site. According to his secretary Masae, Ito's ex-wife's younger brother Yoshimoto visited and he started arguing with Ito, but he suddenly escaped. Kenzo asks Kyosuke Kozu (Masaomi Kondo) to investigate. It turns out that Ito's son Takashi, who was killed, is enrolled in Kyosuke Kamizu's university. When Kyosuke Kamizu met at the university, his mother-in-law, Yoko, aimed at his father's fortune and said, "I think he teamed up with designer Kawahara ." Yoko has a relationship with Kawahara, and Ito, who died, was confused because she had an affair with her secretary, Masae. Takashi is said to have already left home and is living on his own.