Returner (リターナー, Ritana) is a 2002 Japanese science fiction film, directed by Takashi Yamazaki and starring Anne Suzuki and Takeshi Kaneshiro.

Plot

Milly (Anne Suzuki) is a female soldier from the year 2084, when the human race is on the verge of extinction at the hands of an alien race, the "Daggra" (which means "enemy" in the Tibetan language). At the human resistance's final stronghold in Tibet, which is on the verge of collapse at the hands of the Daggra, Milly rushes to a newly-built time portal and leaps into it, just before a flying bomb destroys it. The portal sends her to October 19, 2002, where her mission is to kill the first Daggra who faked a crash landing and stop him from signaling the others - effectively preventing the war which starts on the morning of October 22.

Milly lands in the aftermath of a shootout in Tokyo Bay, Japan, where a hitman named Miyamoto (Takeshi Kaneshiro) finally has the murderous mobster Mizoguchi (Goro Kishitani) at gunpoint. Her arrival allows him to escape and Miyamoto takes Milly, who he believes he has accidentally shot, back to his place. She has been saved by a plate of metal in her coat and with the threat of a tiny bomb taped to his neck, she persuades Miyamoto to aid her in her mission. Miyamoto also has a personal score to settle with Mizoguchi, who killed his childhood friend by kidnapping him with other children and having them killed to sell their organs. Mizoguchi now belongs to a very powerful Chinese Triad.

That night, Miyamoto wakes up and sees Milly placing his trenchcoat on a coat hanger. After she explains that it fell on the floor, he tells her to go away and get back to sleep. The next morning, as Miyamoto prepares to leave, he discovers photos of himself dead and a newspaper article on his death. He shows these to his informant and weapons supplier Shi (Kirin Kiki), who tells him it's a rather elaborate trick that the Triads wouldn't waste their time on.

With the help of Shi, they track down the crashed spaceship, but it has already been taken away by the military to the National Institute of Space Science. The duo try to get to the captured space ship to kill the alien as Mizoguchi arrives with his armed men to take the establishment over. Milly looks at the alien and it is not what she expected. She hesitates to kill it as bullets fly and people die as Mizoguchi advances on the lab.

The alien communicates that it wants to go home, using Miyamoto as its mouthpiece and Milly begins to realize that she has been told a lie. The humans, not the aliens, started the war which exterminated the human race. They did it by capturing and killing this alien. She realizes that they have to stop Mizoguchi from killing the alien as he wants the alien technology to take over Japan and maybe the world. Following a gunfight and the destruction of the Space Science lab, Mizoguchi and his goons take the alien and its ship while Miyamoto and Milly regroup for their next plan to complete her mission.

The duo once again confronts Mizoguchi and his goons at an abandoned oil rig before they successfully rescue the alien. Surviving a huge explosion set off by Miyamoto, a bloodied Mizoguchi threatens to kill the duo and the alien for ruining his plans. However, the bullets he fires are stopped by an invisible force field. Miyamoto acts fast and grabs his gun, killing Mizoguchi in a final gunfight. Before the duo can figure out where the force field came from, a Daggra craft disguised as a Boeing 747SP airliner arrives on the scene, having received the alien's distress signal. The Daggra take their wounded comrade and leave Earth. As the future war has ceased to exist, Milly slowly disappears in front of Miyamoto.

Shortly after the incident, Miyamoto decides to give up his life of violence and hands in his guns to Shi. While walking back home, he is confronted by a thug whose life he had spared earlier at Tokyo Bay. Realizing that he no longer has any guns, Miyamoto is helpless as the thug shoots him. The thug walks away, assuming that Miyamoto is dead. Several seconds later, Miyamoto staggers up and finds his life was saved by a plate of metal similar to one which saved Milly on their first encounter. The plate has a written message by Milly, telling him she has repaid him. Miyamoto recalls the night Milly messed around with his trenchcoat. As it turns out, while Miyamoto and Milly were asleep, another Milly traveled from the future and slipped the metal plate into his trenchcoat before returning to her timeline.