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. [Written by MAL Rewrite]

Takemichi Hanagaki’s second year of middle school was the highest point in his life. He had respect, a gang of friends he could count on, and even a girlfriend. But that was twelve years ago. Today, he’s a nobody: a washed-up nonentity made fun of by children and always forced to apologize to his younger boss. A sudden news report on the Tokyo Manji Gang’s cruel murder of the only girlfriend he ever had alongside her brother only adds insult to injury. Half a second before a train ends his pitiful life for good, Takemichi flashes back to that same day twelve years ago, when he was still dating Hinata Tachibana. After being forced to relive the very same day that began his downward spiral, Takemichi meets Hinata’s younger brother. Without thinking, he admits to his seeming death before flashing back to the past. Takemichi urges him to protect his sister before inexplicably returning to the future. Miraculously, he isn’t dead. Stranger still, the future has changed. It seems as though Takemichi can alter the flow of time. Given the chance to prevent his ex-girlfriend’s tragic death at the hands of the Tokyo Manji Gang, Takemichi decides to fly through time to change the course of the future. [Written by MAL Rewrite]

In Tokyo's downtown district of Ikebukuro, amidst many strange rumors and warnings of anonymous gangs and dangerous occupants, one urban legend stands out above the rest—the existence of a headless "Black Rider" who is said to be seen driving a jet-black motorcycle through the city streets. Mikado Ryuugamine has always longed for the excitement of the city life, and an invitation from a childhood friend convinces him to move to Tokyo. Witnessing the Black Rider on his first day in the city, his wishes already seem to have been granted. But as supernatural events begin to occur, ordinary citizens like himself, along with Ikebukuro's most colorful inhabitants, are mixed up in the commotion breaking out in their city. [Written by MAL Rewrite]