Linebarrels of Iron (鉄のラインバレル, Kurogane no Rainbareru) is a Japanese manga series created by Eiichi Shimizu and Tomohiro Shimoguchi. The series was first serialized in Akita Shoten's monthly shōnen manga magazine, Champion Red, in 2005.It has since been compiled into eleven tankōbon, as of November 20, 2008.The story centers around Kouichi Hayase, a fourteen-year-old boy living a mediocre life, until an accident turns him into the pilot of a gigantic robot called "Linebarrel" and leads him to encounter a mysterious girl.
An anime adaptation of the manga series was announced in the February issue of Animage magazine.The anime is directed by Masamitsu Hidaka and animated by Gonzo. Though the world premiere of the first episode took place at Southern California's 2008 Anime Expo,the series premiered in Japan on the television network TBS (Tokyo Broadcasting System) on October 3, 2008. The anime broadcast a total of twenty-four episodes, the last of which aired on March 20, 2009. To commemorate the series' anime adaptation, Shimizu and Shimoguchi decided to create a one shot manga, recreating the entire first episode of the anime, in which the plot differs in many aspects compared to the beginning of the manga.
The Linebarrels of Iron story takes place in a fictional alternate future, centering on a junior-high school student named Kouichi Hayase, who escaped his daily life of being bullied as a child by daydreaming about being a hero. His life was forever changed during a class trip in the year 2016 when an artificial satellite fell from orbit. Due to this "accident", Kouichi was left in a coma for half a year, and upon awakening, found himself with strange powers, including superhuman strength. Then, in 2019, a mysterious robot called "Linebarrel" appears before him. It is revealed that the accident from three years ago was not caused by a satellite, but rather by the Machina robot Linebarrel, and that this turned him into a "Factor", which is the name given to Machina pilots. This leads him to encounter Emi Kizaki, a mysterious amnesiac girl whose unknown past seems to be related to Linebarrel. He joins her in fighting for JUDA, the world's largest medical equipment maker, which happens to secretly own several other Machina robots.