| John Dickson | Carr | American author. |
| Agatha | Christie | English writer. |
| Arthur | Conan Doyle | British writer. |
| Antony | Gillingham | Lead character in a detective novel. |
| Hayato | Ichiyanagi | Sakue's younger brother. |
| Kenzo | Ichiyanagi | The current master of the house of Ichiyanagi. |
| Eizo | Inoue | Narrator's friend. |
| | Isokawa | Chief investigator. |
| Takataro | Kigi | Novelist. |
| | Kimura | Detective sergeant. |
| Kosuke | Kindaichi | Private detective. |
| Saburo | Koga | The main character from the classic Japanese fantasy Suwa Engi. |
| Fuboku | Kozakai | Novelist. |
| Ginzo | Kubo | Katsuko's uncle. |
| Katsuko | Kubo | Kenzo's fiancé. |
| Rinkichi | Kubo | Katsuko's father. |
| Ruiko | Kuroiwa | Japanese journalist. |
| Maurice | Leblanc | French novelist. |
| A.A. | Milne | British author. |
| Mushitaro | Oguri | Japanese author. |
| Udaru | Oshita | Detective story writer. |
| Ellery | Queen | Novelist. |
| Edogawa | Ranpo | Japanese author. |
| Kyokichi | Shimizu | The three-fingered man. |
| Shizuko | Shiraki | Katsuko's friend. |
| Yosuke | Taguchi | A farmer. |
| Shozo | Taya | Katsuko's ex-boyfriend. Aka: T. |
| Juza | Unno | Japanese fiction writer. |
| Freeman | Wills Crofts | Irish author. |
| Akiko | | Ryosuke's wife. |
| Genshichi | | One of Kenzo's servants. |
| Ihei | | Kenzo's great-uncle. |
| Itoko | | Kenzo's mother. |
| Kiyo | | Itoko's maid. |
| Ofuyu | | Kenzo's lady friend. |
| Old Nao | | Kenzo's cook. |
| Ryosuke | | Kenzo's a cousin. |
| Ryuji | | Itoko's second son. |
| Saburo | | Itoko's son. |
| Sakue | | Kenzo's father. |
| Seno | | Insurance company agent. |
| Shokichi | | One of Kenzo's servants. |
| Suzuko | | Itoko's youngest daughter. |
| Taeko | | Itoko's elder daughter. |
| Tama | | Suzuko's pet kitten. |
