正篇（#1—#12、#17—#25）

黑之时代篇（#13—#16）

十五岁篇（#26—#28）

正篇（#29—）

For weeks, Atsushi Nakajima's orphanage has been plagued by a mystical tiger that only he seems to be aware of. Suspected to be behind the strange incidents, the 18-year-old is abruptly kicked out of the orphanage and left hungry, homeless, and wandering through the city.

While starving on a riverbank, Atsushi saves a rather eccentric man named Osamu Dazai from drowning. Whimsical suicide enthusiast and supernatural detective, Dazai has been investigating the same tiger that has been terrorizing the boy. Together with Dazai's partner Doppo Kunikida, they solve the mystery, but its resolution leaves Atsushi in a tight spot. As various odd events take place, Atsushi is coerced into joining their firm of supernatural investigators, taking on unusual cases the police cannot handle, alongside his numerous enigmatic co-workers.

孤児院を追い出され、餓死寸前の青年・中島敦が出会った風変わりな男たち――。白昼堂々、入水自殺にいそしむ自殺嗜好の男・太宰治。神経質そうに手帳を繰る、眼鏡の男・国木田独歩。彼らは、軍や警察も踏み込めない荒事を解決すると噂される「武装探偵社」の社員であった。何の因果か、巷を騒がせる「人喰い虎」退治への同行を求められる敦だが……。架空の都市　ヨコハマ。登場するは、文豪の名を懐く者たち。その名になぞらえた異形の力が火花を散らす。奇怪千万の文豪異能力バトル、ここに開幕！

고아원에서 쫓겨나 굶어 죽기 일보 직전,

아쓰시가 만난 너무나도 특이한 남자들.백주대낮에 물에 뛰어들어 자살을 시도하는

자살 마니아 다자이 오사무.신경을 곤두세워 수첩을 기록하는

안경남 구니키다 돗포.군인도 경찰도 손대지 못하는

험난한 사건을 해결한다는 그들.운명의 장난인지, 아쓰시는

'식인 호랑이' 퇴치를 요구받는데...항구 도시 요코하마.

문호의 이름을 한 그들과

기이한 힘이 만나, 이야기가 시작된다!...

เด็กหนุ่มผู้ตกที่นั่งลำบากได้เข้าร่วมสำนักงานนักสืบซึ่งเต็มไปด้วยสมาชิกผู้มีพลังเหนือธรรมชาติ พวกเขาไขปริศนาและคอยขัดขวางแผนการร้ายของพอร์ทมาเฟีย