Kampfer was a 12-episode action/ harem comedy TV anime aired from October 2 to December 17 of 2009 in Japan. The anime is based on a light novel series written by Toshihiko Tsukiji and illustrated by Senmu from November 24, 2006 to March 25, 2010. A manga adaptation of the series also written by Tsukiji and illustrated by Yu Tachibana is currently being published in the Japanese seinen magazine, Monthly Comic Alive, since April 2008. The TV anime is currently licensed in America by Sentai Filmworks and is available for purchase on DVD.
Ordinary high school student Natsuru Seno wakes up one day to discover he has transformed into a girl with a stuffed tiger called Harakiri Tiger telling him that he has been chosen to be a Kampfer, female fighters destined to fight each other. Natsuru comes to realize this problem when attacked by a mysterious Kampfer armed with a pistol while on his way to school.
If there are two words that come to mind with Kampfer, it would be wasted potential. While the series does have a somewhat unique premise with its battling schoolgirls story, the series rather quickly sets the premise aside to turn itself into yet another unwanted harem anime.
Natsuru plays out as your typical doormat to the perverted antics and misunderstandings he undergoes with the several girls who have interest in him and is ridiculously dense in knowing the affections of those not named Kaede Sakura. The gender-swapping element to his transformation into a Kampfer adds more mindlessness to the series as Natsuru finds herself (for lack of a better word) getting enough fangirls ogling for her and being subjected to varying degrees of sexual harassment and perverted antics from school club representatives and the female student body admiring her for outer beauty or using the attractiveness of her body to enhance club status. The main group of girls interested in Natsuru don't help matters either as they are mostly nothing more than archetypes that you would find in one form or another in other ecchi, harem, romantic comedy and/ or other high school-based anime.
The unwanted harem element to the series gets so bad that Kampfer is completely lacking a plot for much of its run. The series makes an attempt at a plot for three of its final four episodes regarding the origins of the Kampfer and another group of Kampfer that Natsuru and the girls encounter. But due to how rushed and poorly built up this plot element is and how the new characters get portrayed, the horrible plotting only adds to the mindlessness that Kampfer portrays throughout its run.