Ide of the Kokusai Rayon Company visits a supermarket and finds cheap shirts being passed off as his company's products. But a closer look reveals that the last letter of "Kokusai" has been changed to "n" and reads "Kokusan." The buyers, however, are all under the impression that they are buying Kokusai shirts. Ide begins an investigation to find out where the shirts are being made, but before he is able to uncover anything, he is killed on a train and his little black book, filled with secret data, is stolen. Sugino then starts a one-man search for both the killer and the factory turning out the cheap shirts.
Ken Utsui
Yukiko Fuji
Hideo Takamatsu
Kyōko Enami
Jun Hamamura
Masao Mishima
Yūzō Hayakawa
Machiko Horikawa
Yoshio Takee
Nobuo Minamitaka
Shō Natsuki
Kōichi Itō
Shinji Kawashima
Kanichi Tani
Sachiko Meguro
Rin Sugimori
Toshiyuki Ohara