Dazai Osamu is an exiled executive of the Port Mafia and later becomes a detective at the Agency in the anime and manga series Bungou Stray Dogs. He is known for his eccentric personality and exceptional combat skills. Dazai is characterized by his unpredictable nature, quick wit, and a deep sense of nihilism. He often exhibits a playful and nonchalant demeanor, concealing his past traumas and true feelings beneath humor and a self-destructive attitude. Dazai has a close relationship with his ex-partner and rival, Chuuya Nakahara, and an unspoken understanding with the protagonist Atsushi Nakajima. He harbors a desire to change the world and has a knack for recognizing and exploiting others' talents, often manipulating situations to his advantage.