Based on Matsumoto Seicho's classic mystery novel of the same name, the story centers around a group of detectives who are determined to find the truth behind an apparent double suicide.
| Actor | Role |
|---|---|
 Hiroshi MinamiKiichi Mihara | Kiichi Mihara |
 Isao YamagataTatsuo Yasuda | Tatsuo Yasuda |
 Mieko TakamineRyoko | Ryoko |
 Yoshi KatōJutaro Toriumi | Jutaro Toriumi |
 Takashi ShimuraKasai | Kasai |
 Ushio AkashiHasegawa | Hasegawa |
 Tokue HanazawaNot listed | Not listed |
 Yūji HoriNot listed | Not listed |
 Takashi KandaSayama's brother | Sayama's brother |
 Akiko KazamiNot listed | Not listed |
 Mitsue KomiyaNot listed | Not listed |
 Toshie KusunokiNot listed | Not listed |
 Akitake KōnoNot listed | Not listed |
| JJunji MasudaNot listed | Not listed |
 Masao MishimaNot listed | Not listed |
| SSanae MitsuokaTomiko | Tomiko |
| YYasushi NagataNot listed | Not listed |
| AAkemi NaraNot listed | Not listed |
| MMasahiko NaruseNot listed | Not listed |
 Masao OdaNot listed | Not listed |
 Chiaki TsukiokaNot listed | Not listed |
| KKoji KiyomuraNot listed | Not listed |