Volume 23

Volume 23 was released on April 17, 1999 in Japan.

Movie Theater Case
Anime Episode 138-139: The Final Screening Murder Case

Cruise Ship Murder Case
Anime Episode 174: The Twenty Year Old Murderous Intent: The Symphony Serial Murder Case

Innocent Suspect Case
Anime Episode 156-157: Metropolitan Police Detective Love Story 2

File 231 - Investigation Begins!!
The Detective Boys are going to help Takagi investigate.

Trivia

 * The title for each chapter are worded as the following in Case Closed:
 * File 222 - At the Movies
 * File 223 - The Truth Inside the Mirror
 * File 224 - A Place For Dreams
 * File 225 - The Phantom Schemer
 * File 226 - Murder in Flames
 * File 227 - An Unexpected Target
 * File 228 - Vanished Into the Waves
 * File 229 - The Truth
 * File 230 - A Witness Returns
 * File 231 - Begin Investigation!!