Linebarrels of Iron (鉄のラインバレル, Kurogane no Rainbareru?) is an ongoing 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 2004. It has since been compiled into ten tankōbon, as of September 19, 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", as well as lead 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. 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.