Narumi Fujishima may seem like a normal high school student at first glance, but in reality he is a pessimistic outsider. Due to his father's work, he had to constantly transfer schools, and thus he has never managed to become a part of society. When he is forced to join the gardening club by his cheerful classmate Ayaka Shinozaki, Narumi encounters the genius hacker Alice, who lives in isolation above Hanamaru, the ramen shop where Ayaka works part-time. He then discovers that Alice is running a special private detective agency, and that all her professional associates refer to themselves as "NEET"s: Not in Education, Employment, or Training. Joining the NEET detective agency due to his personal connection with a criminal case, Narumi finds himself entangled in a world of dangerous investigations conducted by the ill-assorted group of detectives, all the while trying to track down the crime syndicate which seems to have mysterious ties to Alice. [Written by MAL Rewrite]

It is the year 2017, and Europe is being invaded by the forces of the Holy Britannian Empire. In an attempt to combat the opposition's overwhelming pressure and put an end to the massive casualties, the army forms a special unit called Wyvern, or W-0, composed of former Japanese citizens referred to as "Elevens." Recruited from ghettos, these young men and women pilot Knightmare frames—humanoid war machines—into dangerous operations where death awaits, hoping to make a name for themselves.

When a European regiment attempting to recapture a crucial city is pinned down by the enemy, it's up to W-0 to bail them out. Among those selected for the rescue operation is Lieutenant Akito Hyuuga, known as "Hannibal's Ghost" due to his prowess on the battlefield. However, the supposed rescue mission becomes suicidal when, in an attempt to take out as many Britannians as possible, the commanding officer initiates the Knightmare's self-destruct sequence. In its aftermath, Akito finds that he is the last one standing…

The story begins when high school student Kazuki Muto is killed one night saving a mysterious girl from a monster, only to wake up in his school dorm, believing it to have been a dream; however, he soon finds out that dream wasn't a dream at all when a giant serpentine monster attacks him and his sister. Tokiko Tsumura, the girl he saved, explains that the monster is a homunculus. Kazuki had been attacked and killed by it when he was rescuing her; however, she, feeling responsible for him, revived him by placing a Kakugane medallion in his chest, serving as a replacement heart. The Kakugane, as Tokiko explains, is an alchemical device that, when activated, takes a certain form based on the Kakugane's user, forming a unique Buso Renkin. The Buso Renkin is the only thing that can destroy a homunculus monster. Using this, Kazuki creates his own Buso Renkin (the "Sunlight Heart," a huge lance). Along with Tokiko and her own Buso Renkin (the "Valkyrie Skirt," an execution scythe), Kazuki joins the fight against the homunculi and their master.

One will to create oceans. One will to summon the mulberry fields. One will to slaughter countless devils. One will to eradicate innumerable immortals. Only my will… is eternal. A Will Eternal tells the tale of Bai Xiaochun, an endearing but exasperating young man who is driven primarily by his fear of death and desire to live forever, but who deeply values friendship and family. (Source: Novel Updates)