Bungou Stray Dogs: Dazai Osamu no Nyuusha Shiken

Doppo Kunikida is a principled detective working for the Armed Detective Agency, an organization that tackles cases too perilous for the police. His routine is disrupted when he is assigned to work with Osamu Dazai, the agency's new and unconventional recruit, who is preoccupied with self-destruction. Their initial assignment proves more challenging than expected, with the Port Mafia appearing to be involved. Taking place two years prior to the main series, the story details the development of their unlikely partnership, which eventually becomes one of Yokohama's most effective detective teams.