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]

"Mushi": the most basic forms of life in the world. They exist without any goals or purposes aside from simply "being." They are beyond the shackles of the words "good" and "evil." Mushi can exist in countless forms and are capable of mimicking things from the natural world such as plants, diseases, and even phenomena like rainbows. This is, however, just a vague definition of these entities that inhabit the vibrant world of Mushishi, as to even call them a form of life would be an oversimplification. Detailed information on Mushi is scarce because the majority of humans are unaware of their existence. So what are Mushi and why do they exist? This is the question that a "Mushishi," Ginko, ponders constantly. Mushishi are those who research Mushi in hopes of understanding their place in the world's hierarchy of life. Ginko chases rumors of occurrences that could be tied to Mushi, all for the sake of finding an answer. It could, after all, lead to the meaning of life itself. [Written by MAL Rewrite]

To the average person, psychic abilities might seem a blessing; for Kusuo Saiki, however, this couldn't be further from the truth. Gifted with a wide assortment of supernatural abilities ranging from telepathy to x-ray vision, he finds this so-called blessing to be nothing but a curse. As all the inconveniences his powers cause constantly pile up, all Kusuo aims for is an ordinary, hassle-free life—a life where ignorance is bliss. Unfortunately, the life of a psychic is far from quiet. Though Kusuo tries to stay out of the spotlight by keeping his powers a secret from his classmates, he ends up inadvertently attracting the attention of many odd characters, such as the empty-headed Riki Nendou and the delusional Shun Kaidou. Forced to deal with the craziness of the people around him, Kusuo comes to learn that the ordinary life he has been striving for is a lot more difficult to achieve than expected. [Written by MAL Rewrite]

Lucy is a special breed of human referred to as "Diclonius," born with a short pair of horns and invisible telekinetic hands that lands her as a victim of inhumane scientific experimentation by the government. However, once circumstances present her an opportunity to escape, Lucy, corrupted by the confinement and torture, unleashes a torrent of bloodshed as she escapes her captors. During her breakout, she receives a crippling head injury that leaves her with a split personality: someone with the mentality of a harmless child possessing limited speech capacity. In this state of instability, she stumbles upon two college students, Kouta and his cousin Yuka, who unknowingly take an injured fugitive into their care, unaware of her murderous tendencies. This act of kindness will change their lives, as they soon find themselves dragged into the shadowy world of government secrecy and conspiracy. [Written by MAL Rewrite]