Osamu Dazai — the heir to the Port Mafia’s leadership, Mori’s closest confidant since the age of fifteen, and the greatest fear of anyone awaiting torture in captivity. Suddenly, he misses an executives' meeting and fails to show up during the day. When Chuuya arrives to check on him under orders, he finds the apartment trashed.
And on the wall, "Goodbye" is written crookedly in a child's chalk.
Dazai has vanished from the Port Mafia, leaving his paycheck behind but taking too many secrets with him. Yet, Mori is in no hurry to find him.
No report was filed on the incident, and no manhunt for a traitor was ever launched.
All records of his crimes mysteriously vanished that very night. It seemed as though nothing of Osamu remained — except for Chuuya’s car, burning as a "parting gift," and a small pool of blood in the bathtub.
The official version: a defection, followed by death at the hands of enemies.
But Dazai knows that Mori, Akutagawa, and perhaps Chuuya won't accept his "death" so easily. The Boss simply let him go, hoping he wouldn't reveal their secrets. Osamu won't — even if he ends up working for a rival organization.
But while his partner comes to terms with his death, he cannot leave them unsupervised.