A woman died a suspicious death in the forest. Beside her, the sword-smith Amon finds a new-born boy with a tragic fate and takes him in. About 10 years later, this boy who is named Gai and who has become Amon's apprentice, loses his right arm in an accident while making a sword. Amon decides to take a sword called "Shiryuu," which is a sword with demonic powers that has been passed down for generations, and fashion it into an artificial arm for Gai. That was the beginning of it all... The story of this boy, who has become one with a demonic weapon and is drawn into a cruel fate in which he must face countless battles, can be seen as either the story of "a beautiful weapon and an ugly person" or of "the cruelty of weapons and the beauty of humans." This is a completely new world of comic noir.
Shoshidai's new weapons are no match against the demonic powers of Zsoltgewinn, pitting Ichijo and Gai against Miura in a fierce battle.
An abandoned baby boy is adopted and named Gai by swordsmith Amon. He becomes an apprentice, later losing his arm in a ritual gone horribly wrong.
Ichijo attempts to test Gai's potential as a Chrysalis but is interrupted by a member of the Gabi, a group that has long fought Busoma.
Shoshidai, an organization tasked with collecting cursed weaponry, dispatches two of its agents to retrieve the legendary Demon Sword Zsoltgewinn.
The Shoshidai reawaken their most powerful Chrysalis, Seiya Ichijo. After Gai's powers partially awaken, his mind reverts to that of an infant.
With his soul possessed by a demonic spear, Tatsumi transforms into a monstrous entity called a Busoma. Miki takes Marcus to Shoshidai headquarters.
Miki and Marcus are sent on a covert mission by the Shoshidai to infiltrate and retrieve an ancient weapon of the fairy world: the legendary Halbert.
With Gai in tow, Ichijo heads to Shoshidai headquarters before stopping to meet his lover, Kei. A mysterious sword appears before gamer Midoriko.
A wealthy widow hires a search vessel to find the lost treasure of pirate Throlla, who reportedly also kept a mythical weapon known as Gallon's Hammer.
After acquiring the Azoth Sword, Miki is ambushed by Marcus and Miura. Amon forges a prosthetic arm out of the sword Shiryu to replace Gai's lost limb.
After Gai is safely brought to Shoshidai headquarters, Ichijo is ordered by Kagami to cold sleep due to his rapidly progressing change into a Busoma.
A depressed Sayaka questions Amon about Gai's motives. Meanwhile, Ichijo reveals to Gai how he came to harness the power of the Chakram.