It has developed a cult following in America.

Ami Hyūga was an average high school girl, trying to lead a normal life but her world came crashing down when her brother Yu and his friend Takeshi Sugihara were killed by bullies led by Sho Kimura. As Ami tracks down Sho, she is surprised to discover the bullies' association with a sinister ninja yakuza family. When she goes after her revenge, she soon finds herself in over her head with her left arm lost as a result. Barely surviving, Ami escapes and seeks out shelter from Takeshi's parents Suguru and Miki Sugihara, two kindly garage mechanics who fit her with a high-powered machine gun prosthetic. With Miki's use of chainsaw, Ami proceeds on a killing spree against the murderers of their loved ones.

Eventually, they reach the place where the yakuza are hiding. As the fight continues, Miki loses her right foot and eventually dies. Ami loses her machine gun doing her fight with Sho's father Ryūgi Kimura but gets Miki's chainsaw. Finding Sho with hostages to keep Ami at bay, his mother Violet Kimura manages to disarm Ami while attempting to kill her with her drill bra. However, noticing one of the student hostages wet himself, Ami takes advantage and trips Violet onto the urine to cause the mother's electrocution as Ami manages to kill Sho. Though she attempts to commit suicide with nothing left for her, Ami hears noise behind her and the film ends as Ami turns, sword at the ready.

According to writer and director Iguchi, the idea for The Machine Girl went back to a simple idea he had about a one-armed girl in a bikini looking for revenge. The idea for the machine gun arm came later.

The U.S. Version was dubbed at NYAV Post, with several well known anime voice actors such as Jason Griffith and Dan Green.

The movie premiered at the Yubari International Fantastic Film Festival in March 2008. It was released theatrically in the United States on May 23, 2008 and on DVD June 3, 2008. The first theatrical release in Japan was on August 2, 2008. The Japanese DVD from Nikkatsu came out January 23, 2009 as a 2 disc set including the short Shyness Machine Girl (hajiraiマシンガール, Hajirai mashin gāru?). Tokyo Shock, the Media Blaster label which released the original US DVD announced that they were bringing out a 2 disc special titled The Machine Girl Remix on August 4, 2009. The set includes the Shyness Machine Girl short renamed as Machine Girlite.

Although it has many times been compared to Robert Rodriguez's Planet Terror by critics, the film's reception has been mixed. It currently holds a 63% "fresh" rating on Rotten Tomatoes from 8 reviews.

The movie was rated 18 in countries such as Chile, Peru and Spain because of nonstop gore, bloody action sequences and a suggested rape scene.

A direct to video sequel called Shyness Machine Girl (hajiraiマシンガール, Hajirai mashin gāru?) was released on January 23, 2009 along with the Japanese DVD of The Machine Girl.