Taking place several years after the events in the original Kite film, Kite Liberator starts off with crew members of ISS along with Kōichi Doi, a food formulation researcher at Defy Foods, returning back to the Space Station on a Kudryavka shuttle. Doi had been researching various methods of preserving bone mass in zero gravity conditions, leading to healthy but frequently unappetizing food. While some members of the crew voice their distaste, the mission leader Orudo Noguchi reminds them of the necessity and benefits of the space foods. However, when it is found that Noguchi and another crew member have space radiation exposure and abnormally increased bone volume during a periodic medical check-up, Doi strangely questions the safety of his food, hinting that there may be more going on that is apparent. The two men are ordered by the doctor to discontinue any further missions to prevent further radiation exposure. In his room, Noguchi observes pictures of Monaka, his only daughter and gives Doi a small package to deliver to her.
Meanwhile in Tokyo during night time, two police officers pursue a violent pedophile through the streets and into a train station. The criminal enters a women's washroom and takes a young girl hostage after shooting two bystanders. The officers attempt to defuse the situation but are rebuffed with gunfire. The criminal forces the young girl into a stall, with the intention of fondling/raping her. However, the lights go out and the criminal is attacked and killed by the "Angel of Death", a female assassin. Hearing gunfire, the officers enter but find only the assassin's calling card: a flurry of white feathers on the dead suspect. Escaping the station on an outbound train after changing clothes, it is revealed that the "Angel of Death" is none other than Monaka Noguchi.
That same night, Monaka Noguchi, who is actually the Angel of Death, goes to work at Apollo 11, a maid cafe usually patronized by the same perverted customer who enjoys harassing the waitresses sexually. While she is not on a mission, Monaka plays a nerdy, but very coy clumsy gentle high school girl. And because the nature of her work place, she is easily targeted of harassment from customers and flirtations from the manager. "the customer is always right," implies their sleazy manager. However, Mukai, the mysterious oldest associate, does not take kindly to such behavior and retaliates such as putting spicy Habanero in drinks or kicking a rude customer in the groin. It is never explained why the Manager never fires her, but it is speculated Ms. Mukai (who bears a striking resemblance to Sawa) is, or was, more than just a waitress there and looks after Monaka. While they are working, the sleazy manager received a phone call from the real Tsuin, the older brother of the criminal the Angel of Death killed at the train station, stating his younger and only brother was murdered by Gaga. When Monaka returns home from work, she receives a package from Azuki, her cousin. While Monaka opens the package, Azuki gets a Häagen-Dazs ice cream from the mini fridge. Azuki becomes jealous at the discovery of Monaka's gift; a bracelet made of rocks from Mars. Monaka then approaches her window, looks up at the night sky, and thanks her Father.
Back at the Space Station, Orduo and the other crew member's condition have gotten worse. Their bone volume have increased again. The Doctor realize the cause of this was due to Sun's radiation and Mr. Doi's space food. The infected bodies are becoming abnormally large due to the growing bones. As Orduo groans in agony and semi-conscious, he thinks about his daughter and we see a brief flash back on Earth with a kid Monaka and him. The next morning, Monaka logs into her laptop and goes to a secret folder where it contains a list of targeted people. On her way to school, she stops by at the apartment complex where her next target lives and proceeds on her way. During the day she sees Mukai walking with a child, and is told by her sleazy manager that Mukai is a single mother, the father is unknown. When evening arrives, she then returns to the area to kill her next target, the owner of the apartment complex for his murderous crimes of killing several people. Disaster strikes at the Space Station. Orudo and the crew member have transformed into homicidal monsters, successfully killing most of crew members and ISS Police units. Prior to escape, they were able to kill one of the monsters by blowing up the Space Station. However, the second monster was no where to be found. Only the Doctor, Mr. Doi, Orudo, and couple others escaped in Space Pod back to Earth. The crash landing to a building drew Defy Food Company's attention and hired agents to solve problems and rid any evidence that may jeopardize their reputation.
That night, back at Apollo 11 maid cafe, the perverted customer was back and tried to fondle Monaka, but Mukai intervened and sent the injured customer to a hospital. Due to obstruction of business, Mukai is held liable and has to pay for the hospital bills. After work, Mukai invites Monaka out in the back for small fireworks. They had an interesting, but vague, discussion of Mukai's life. After saying good bye, Monaka runs into Gaga, who was waiting for her by the steps. When he tells her she was a minor and he was a police officer, she tried to reason with him, even offering a free drink next time. In return for his silence, and having a secret crush on her some time, he finally asks her out. She obliges. Meanwhile, a monster emerges out of the sea near downtown. In a hotel room, agents are demanding silence from the Doctor and Mr. Doi. When they receive news about a monster roaming around the city, they inform the space chef about it, basically blaming him. Mr. Doi, feeling guilty, protests it wasn't his fault. The next day, at a local park, Sputnik, dressed entirely in an animal costume (cat) from head to toe, meets up with Monaka. Her current assignment gets postponed and she is given a new one: To eliminate the monster. In the next scene we see Monaka as the Angel of Death collecting weapons. Her sleazy Manager realize she favors "Red Club" (The gun of Destiny), which was used by the previous assassin like her. The Manager adds that the gun was made by a friend of his who died at the same time of the assassin's disappearance several years ago. "I see...what was her name?" was all Angel of Death says. Although it isn't answered, we know it was Sawa.
At Gaga's apartment that same night, he gets attacked by the older brother, Tsuin. The two engage in a gun fight. Sensing he is unable to easily kill the officer, he flees. It becomes a chase, just like with his younger brother. Not so far away, the monster is causing havoc. The Angel of Death uses a Sniper rifle from a roof top first but after few shots, she ceases firing and sees the monster unharmed. She gets closer by using a grappling hook and then fires an automatic weapon at it. And when that doesn't kill it, she uses her Red Club, but even the explosive bullets do not cause sufficient damage. After running out of options, she feels beaten and retreats by using the grappling hook back to the rooftop. She tried to escape, but the monster eventually pins her against a wall, the impact causes one of her contact lenses to fall off. Thinking this is the end, she waits for her death, but it never comes. Just as her Nemesis is about to finish her off, it sees and recognizes the bracelet. When she sees her chance to escape, she fired a few bullets into its mouth and sends it flying backwards to the lower street level where it falls on top of a car. Badly injured, the monster tried to show sympathy toward Angel of Death. However, she is too stunned to do anything but stand there. The car explodes. Doi persuades her to get in his car with two agents. The agents take them to an isolated indoor parking lot, discussing the incident. She learns that the monster she was sought out to kill was actually her mutated father.
The two agents try to shoot her, but she kills them demands answers from Mr. Doi. The two men pretended to be from NASA, but were really agents to keep things under control and get rid of any evidence. After shooting Mr. Doi execution style, she runs back to the area where she fled from her father. However, she runs into Tsuin who takes her hostage as Gaga gets closer. Tsuin threatens to kill her if he comes any closer. Unfortunately for Tsuin, the hostage is a skilled assassin. She is able to break free easily and ends up killing him before Gaga arrives. After discovering the body, he tried looking for the hostage, finding only a dark ribbon on the ground nearby. Outside, Monaka gets tired from running and catches her breath. While she was regaining her strength, a passing truck explodes. The monster has regenerated itself and the two meet once again. It is unknown what happens next as the screen goes black and the closing credits roll.
- Marina Inoue as Monaka Noguchi
- Akemi Okamura as Manatsu Mukai
- Masakazu Morita as Rin Gaga
- Setsuji Satō as Kōichi Doi
- Kei Shindō as Azuki Noguchi
- Mugihito as Torokurō Amuzu
- Yasuhiro as Kai Tsuin, Kichi Tsuin
- Xanthe Huynh as Monaka Noguchi
- Tara Platt as Manatsu Mukai
- Grant George as Rin Gaga
- Doug Erholtz as Kōichi Doi
- Melanie Wagner as Azuki Noguchi
- Joe DiMucci as Torokurō Amuzu
- Derek Stephen Prince as Kai Tsuin, Kichi Tsuin
- Kaiji Tang as Sputnik