Land of Tanabata

A species of parasitic aliens descends on Earth and quickly infiltrates humanity by entering the brains of vulnerable targets; insatiable beings that gain total control of their host and are capable of transforming themselves to feed on unsuspecting prey. High school student Shinichi Izumi falls victim to one of these parasites, but the creature fails to take over his brain and ends up in his right hand.

A supernatural system allows people to take revenge by having other people sent to Hell via the services of a mysterious entity and her assistants who implement this system. Revenge, injustice, hatred, and the nature of human emotions are common themes throughout the series.

The story centers on Keitarou Gentouga, who has the ability to be a spirit medium. In junior high school, he got someone else wrapped up in a spirit possession incident, and he has been a shut-in for more than two years. As he reintroduces himself to society as a private tutor, he meets a genius girl named Yayoi Houzuki. Yayoi is instantly able to tell that Keitarou has skill as a spirit medium, and she invites him to go with her to a haunted location. The two then start their journey capturing evil spirits.

Ten years ago, a mysterious spatial anomaly now known as "Heaven's Gate" appeared in South America, shortly followed by the opening of "Hell's Gate" in Tokyo altering the sky and wreaking havoc on the landscape. The real stars disappeared, replaced by false stars. During this time, people possessing various special abilities — called "Contractors" — emerged, each capable of different supernatural feats. Following the disastrous Heaven's War, the United States lost its dominant position as a superpower to a mysterious organization named the Syndicate. The story revolves around a Chinese contractor codenamed "Hei" as he undertakes various espionage and assassination missions in Tokyo.

Spurred by the flame raging in his heart, the Black Swordsman Guts continues his seemingly endless quest for revenge. Standing in his path are heinous outlaws, delusional evil spirits, and a devout child of god. Even as it chips away at his life, Guts continues to fight his enemies, who wield repulsive and inhumane power, with nary but his body and sword—his strength as a human.

In the year 2024, the world has collapsed. Grotesque monsters lurk amongst the ruins of Japan, while remaining people scrape together what they can to survive. Kiruko, an odd-job girl in Nakano, accepts a mysterious woman's dying wish to take a boy named Maru to a place called Heaven. Maru is convinced that there will be a boy there who looks exactly like him.