The FLCL Omnibus manga volume is based on the anime OVA series; Hajime Ueda was given permission to create this manga and to take some unique deviations from the anime’s storyline.
Dark Horse Manga has the North American distribution rights for the omnibus, and released this volume in 2012. There isn’t a rating published anywhere on this volume; however, due to the sexual and violent nature of this volume’s content, I would recommend FLCL for manga readers who are 16 or 17 years of age and older.
FLCL is set in a town where the big medical equipment manufacturer Medical Mechanica built a factory. At the beginning of the story, Naoto, a sullen local boy, says that he lives in a boring town and that nothing exciting ever happens. Unfortunately for Naoto, however, his life will suddenly become more exciting than he ever expected.
Mamimi, a high school girl, is suddenly showing an interest in Naoto. She was interested in Naoto’s older brother, Tasuku, who has left to play professional baseball in America; Mamimi sees Naoto as a substitute for Tasuku. As they’re talking, Naoto is suddenly attacked by a woman riding on a Vespa scooter who uses a Rickenbacker guitar as a weapon.
It turns out the woman is a space assassin named Haruko Haruhara, and she’s an extraterrestrial investigator for the Galactic Space Police Brotherhood. She’s on a mission to track down Atomsk, the most powerful space pirate in the galaxy. Unfortunately, when she hit Naoto on the head with the guitar, she created an N.O. portal that can be used by armed robots.
Haruko moves in with Naoto and becomes his family’s maid. As the plot progresses, the mayor’s daughter, Ninamo, also becomes involved in the story. Without giving away any spoilers, I can tell you that FLCL builds into a very crazy sci-fi story.