Azure Apostle Arc

Azure Messenger Arc is the third background arc of Bungo Stray Dogs. It tells the entrance exam of Dazai in order to join the Armed Detective Agency with the help of Doppo Kunikida.

Summary
Doppo Kunikida is an idealist and a straitlaced detective at the Armed Detective Agency, he's paired up with the agency's newest hire: a suspicious, eccentric, suicide-obsessed man named Osamu Dazai. Their first case together turns out to be far more complicated than Kunikida anticipated -- and it looks like the detective agency's sworn enemy, the Port Mafia, is somehow involved, too!

Appearances
Legend: ☆ Not originally appears in the novel, but appears in the anime ★ Appears in the novel, but doesn't appear in the anime ✶ Did not appear physically but was mentioned/conversed to

Chapters

 * From the ''[[Bungo Stray Dogs: Osamu Dazai's Entrance Exam

]]'' novel
 * Prologue
 * Chapter I
 * Chapter II
 * Interlude I
 * Chapter III
 * Chapter IV
 * Interlude II
 * Epilogue

Episodes

 * Episode 6 - The Azure Messenger
 * Episode 7 - Love for the Disease Called Ideals

Impact

 * In the original novel, Dazai passed the entrance exam.
 * Nobuko Sasaki reveals herself as the Azure Messenger.
 * Rokuzō Taguchi dies.

Differences

 * In the original novel, Atsushi is not part of the story.
 * It originally happens before Dazai joined the agency, however in the anime, it happens when Atsushi and Dazai had already joined the agency.