In 2015, the Luxion fleet is attacked by Space Monsters. Admiral Yuzo Takaya gives an injured Koichiro Ohta the last place on the Luxion’s escape shuttle. On the Luxion’s bridge, Yuzo apologizes to his daughter Noriko before the ship explodes. Six years later, Noriko watches other pilot trainees doing exercises in their RX Trainer machine weapons. Her friend, Kimiko Higuchi, joins her and notices she’s watching Kazumi Amano. Noriko says she wants to be like Kazumi, but Kimiko reminds her they’re just beginners. Noriko asks what her horoscope is, and Kimiko says that she’ll have a special encounter. Kimiko also reminds her that it’s time for the next period and that they’ll meet their new Coach who turns out to be Ohta. He turns off the RXs’ auto balancers and they all loose balance except for Kazumi. Ohta orders them to do 50 laps but Noriko forgets how to run. She dances around before Ohta tells her to do the laps with her own feet. The next morning Noriko gets a call and at school it’s confirmed that she was selected to be a pilot representative. The other students gossip about how she was unfairly selected and she runs away. Kazumi questions Ohta about it and he says he’s a survivor from the Luxion and that he’s responsible for what happens. He adds that Noriko has the potential to pilot the Buster Machine. Noriko begs Ohta to change his mind but he takes her and shows her Kazumi running with iron sandals. He says that Kazumi does have talent, but her hard work is what brings out that talent. He says Noriko is lacking ability because she doesn’t work at it. He explains he chose her because of her raw potential. He tells her to work hard and go into space with Kazumi, because she has something she has to do. The space station Silver Star detects an object approaching at near light speed, and Ohta and Tatsumi Tashiro wants to investigate it. They decide to send two machine weapons on light speed boosters to check it out and Ohta suggests Noriko and Kazumi. Tashiro thinks Jung Freud would be a better choice, but Ohta says they’re both candidates for Gunbuster. He wants them to experience light speed travel. He briefs the girls on the mission and tells them that for every minute they’re out there, three months will pass on Earth. He warns them to be careful or they’ll end up like Rip Van Winkle. Noriko and Kazumi launch, followed shortly by Ohta in another ship. They meet up with the target and discover that it’s the remains of the Luxion. Noriko enters the Luxion and discovers there’s still air. She also sees that according to the ship’s clock, only two days had passed since the battle. Ohta retrieves Kazumi and goes after Noriko in his RX-7. He tells Kazumi to decelerate if he’s not back in three minutes. Noriko calls for her father and Ohta sees she’s headed for the bridge. Noriko opens the door to the bridge only to find empty space.
Ohta grabs her and carries her out of the Luxion. Kazumi recovers them and informs Ohta that they’re twelve seconds late. Later, Noriko thinks about how her father returned for her birthday like he promised. Noriko remembers when she was young she told her father that she’ll go to space too so she could always be with him. In deep space on board the battleship Exelion, Noriko writes a ‘telepathic letter’ to Kimiko about their journey. Noriko studies on a train and Smith Toren tells her that all that stuff is useless in real combat. She says that she and Kazumi are the best team in the Top Squadron and that a solo like him wouldn’t understand. While Noriko practices in her RX she accidentally turns her monitor on and overhears Kazumi telling Ohta not to let Noriko into combat. Ohta refuses, so Kazumi says she won’t be Noriko’s partner anymore. Noriko is shocked to hear this. Noriko finds Smith at the vending machines and apologizes because now she’s a solo too. Smith says they should be partners then and Noriko agrees. The Exelion fleet enters combat and opens fire as the Top Squadron is launched equipped with californium nuclear warheads. Kazumi and Jung launch as a pair, followed by Noriko and Smith. Once in space, Noriko panics a bit, but Smith’s voice reassures her. He says he’ll handle offense while she handles defence. One of the ships is sunk and Noriko is hit with the shockwave. Several enemies fly past her and she is unable to do anything. After things quiet down, she calls out to Smith, but he doesn’t answer. Noriko returns to the Exelion and waits for Smith, but he doesn’t show up. The Exelion warps away and Noriko peeks into the boy’s dormitory, but doesn’t see Smith. She goes to the vending machines and then the hanger where she sees a room with the lights on. She enters it to find Ohta and the incomplete Gunbuster. She cries into Ohta’s chest, saying she was with Smith but she couldn’t do anything. She begs him to train her harder. Noriko trains in an RX-7 that has a cockpit system that mimics her movements. During warp the fleet comes under attack. Tashiro doesn’t know how that could happen and orders the ship to fire. He asks about the other ships, but is told there’s no way to know until they exit warp. The ships warp out and Tashiro says it will paint a bullseye on Earth.
The Top Squadron is prepared to launch, but there is a problem with Linda Yamamoto’s machine. Ohta tells Linda to use Noriko’s machine and for Noriko to remain on standby. The RX-7s launch while Noriko waits in her room. The Exelion and RX-7s get swarmed by Space Monster grunts and Jung and Kazumi get caught. Noriko cries in her room about how no one had faith in her, but she can’t blame them because she’s such a cry baby. She wonders if she’ll die like that. Linda gets killed by a grunt. Noriko eventually stands up. The Exelion’s bow gets destroyed and their radar is knocked out. Noriko tells Smith that the old her with die with him and that she won’t cry anymore. She says she’ll relay on herself. The Exelion takes more damage and Tashio says they’ll ram the enemy mother ship if they have to. Tashiro is informed that the seventh hanger has opened and Noriko rises up in the Gunbuster. Tashiro tells her not to go, but Ohta tells her to focus on the enemy leader. Gunbuster launches and Noriko uses the Buster Beam to destroy the grunts, freeing Jung and Kazumi. The last of the Exelion’s escort ships is destroyed. Noriko tries to hit the leader with Buster Beams, but it moves too fast for her. She activates her inertial cancellers to full and lets the Space Monster impale Gunbuster. She then uses the Buster Colliders to destroy the Space Monster. The Exelion’s radar is restored and they see that the enemy fleet has retreated from the Sol System. Everyone rejoices when they see that the Gunbuster also survived. On Earth, it is now the year 2032. Kazumi and Noriko are given a late graduation from Okinawa Girl’s Space Pilot High School after they return from space. Noriko thinks about how she was only gone for four months, but ten years had passed on Earth. Reiko Kashihara is now an instructor at the school. After the ceremony, Noriko wonders if she should feel privileged to graduate at seventeen, but Kazumi reminds her that she’s twenty-seven according to her birth certificate. Noriko passes a mother and child, and recognizes the mother as Kimiko. Kimiko, who is now Kimiko Akai, brings Noriko up to speed on their friends while her daughter Takami plays in a sand box. Noriko sees something in orbit and Kimiko tells her it’s the battleship Eltreum. She says it’s an Earth evacuation ship. Kimiko asks Noriko if she can use her connections to make sure Takami can get a spot on the Eltreum. A large mass of enemies that blot out space is detected outside the Sol System. In her room, Noriko is informed that Ohta wants to see her. Kazumi argues with Ohta, which ends with Ohta slapping Kazumi.
Noriko sees this and Kazumi walks out with tears in her eyes. Ohta coughs up blood and collapses. Noriko tries to call an ambulance, but Ohta stops her. He says not to tell Kazumi about it or he’ll kill her. He tells her about the incoming enemy fleet and that Gunbuster is their only hope. He says that together with Noriko and Kazumi, Gunbuster is invincible. He apologizes for not being able to protect Noriko’s father and asks Noriko to keep his illness a secret from Kazumi because she wouldn’t be able to fight if she knew. He asks Noriko to protect her. Noriko wonders if she can protect Kazumi and realizes that she already knows about Ohta’s illness. In the Imperial city of Tokyo, the military brass tries to plan their next move. The Eltreum isn’t ready and they don’t know what else to do. Ohta barges in and says he has a plan. He proposes sending in the decommissioned Exelion and self destruct it, making an artificial black hole to suck in the Space Monsters and the planetoid Jupiter 2. He says the Buster Machines will escort it and that it’s the only option available to them. Noriko and Kazumi head to Tokyo for the mission. Noriko tries to make small talk, but it doesn’t go so well. Kazumi says six months will pass on Earth while they’re gone. Noriko asks about Ohta’s condition, but Kazumi says they have the lives of billions to worry about. Noriko is glad to see Kazumi acting like her old self. As Buster Machines #1 and #2 prepare to launch, Ohta arrives to see them off. Noriko tells Kazumi and asks if Kazumi will marry him when she gets back. Noriko says they make a great couple and that Ohta will need some one to take care of him. Kazumi tells Noriko that Ohta has space radiation syndrome. He might not live six more months. The Buster Machines take off and rendezvous with the unmanned Exelion. They head into the enemy fleet. The Buster Machines start clearing a path to the center of the Space Monster fleet and Noriko sees that four months have already passed on Earth. Kazumi can’t take it anymore and she goes into reverse. The Exelion gets impaled with two Space Monster boarding vessels. Kazumi cries that even if they make it back to Earth, Ohta will be dead and she never got a chance to say she loves him. That time they were arguing, she was hoping he would kiss her and say he loved her. She says she can’t stand that she’ll never see him again. Noriko tells her to pull herself together, saying that Ohta probably wanted to be with her, but had to forsake himself so Gunbuster could succeed. They have to make the most of his last six months and fight. Kazumi understands and decides to fight so she can live in the same time as Ohta. They combine their Buster Machines into Gunbuster. Noriko uses the Super Lightning Kick to break through the Space Monsters and land on the Exelion.
Noriko sweeps the area with the Buster Beam. A group of 3,000 come from below, but Noriko destroys them all with her Homing Laser. She uses Buster Missiles to destroy a cruiser-class and leads the others away from the Exelion. A mass of lasers head towards them, but Noriko blocks them all with the Buster Shield. She then blows them all away with Buster Beams. Two mother ship class Space Monsters try to crush them, but they are destroyed by the Double Buster Collider. The Exelion makes it to the center of the Space Monster fleet, where it becomes a black hole and sucks them all in. News of the mission’s success reaches Tokyo, where they say that the shockwave will hit them in six months. Gunbuster lands outside a hospital, where they find Ohta still alive. Kazumi jumps into his arms and says she loves him. Noriko leaves them alone and apologizes to Smith because she said she wouldn’t cry anymore. She asks her father if Kimiko would be proud of her. Fifteen years after the battle of the Absolute Defence line, in Okinawa, Kazumi Ohta pays her respects to her late husband’s grave. She meets with Reiko, who says space is a strange place because they were classmates, but Reiko is now ten years older. Reiko asks why Kazumi volunteered for a new mission when she’s already hero. Kazumi says she was only able to fight because of Noriko. Kazumi’s students give her a paper crane tree as a going away present and Takami gives her a letter to give to Noriko. Kazumi heads to Hawaii where she is met by a staff officer for Project Carneades. They take a ropeway into orbit, where Kazumi sees that they haven’t restored Australia yet. The staff member explains they’ve put all their resources into the Black Hole Bomb. He says they’re lucky that the Exelion’s explosion only destroyed three planets and caused Earth’s axis to fluctuate. He wonders if humanity has the right to use the Black Hole Bomb to destroy the center of the galaxy. Kazumi says humanity will be destroyed if they don’t. The staff member thinks that if that’s their fate, then so be it. Kazumi says all they can do is survive at any cost. The Black Hole Bomb, Buster Machine #3 comes into view and Kazumi thinks of how she’ll ride it to see Noriko. Near the center of the galaxy, as part of the Galactic Core Assault fleet, is the battleship Eltreum. On it, Noriko joins Jung in meeting admiral Tashiro. He tells them they just need to wait for the main force to arrive. Noriko wonders who will be piloting Buster Machine #3. Buster Machine #3, with Kazumi at the helm, enters warp and warps out at the Galactic Core Assault fleet. Tashiro is amazed that humanity was able to build something so big. Kazumi arrives on the Eltreum and immediate runs to Noriko. Later, they reminisce and Kazumi is reminded that although it was fifteen years for her, it was only six months for Noriko. She gives her the letter from Kimiko, which asks Noriko to return home while Takami is still alive. A holographic picture of Takami was also included. Noriko starts crying. Tashiro briefs everyone on the plan to protect Buster Machine #3, which contains Jupiter, until it can implode. The fleet prepares for battle and launches the mass produced Gunbusters, the Sizzlers.
Jung slaps Kazumi, saying she always takes what Jung wants and gives her the key to Buster Machine #2. She says both Ohta and the Buster Machine are Kazumi’s. Noriko tells her father that the war that began with his ship will soon be over. Kazumi tells her that she’ll be the pilot of Buster Machine #2 and Gunbuster launches. Tashiro asks his XO if he believes in God, but the XO says he doesn’t. Tashiro says he does and adds that at such a close distances, the Space Monsters shouldn’t be able to warp. He’s proven wrong as Space Monsters warp out and try to ram Buster Machine #3. The fleet attacks, but the Super-Exelion class ships are unable to hold them off. The Space Monsters ram Buster Machine #3’s barrier and self destruct. Kazumi says there are too many enemies, so Gunbuster separates. More Space Monsters warp out and self destruct, destroying the barrier. There are only twenty-two minutes left until the Black Hole Bomb implodes. A fierce battle between humanity and the Space Monsters ensues. Afterwards, all three Buster Machines as well as the Eltreum are operational. The count down for the implosion hits zero, but nothing happens. Tashiro is informed that not all of the slave generators are functional and the only way to trigger the implosion is the cause a chain reaction in the core. Tashiro wonders if there really is a God, and Noriko says she’ll make a miracle happen. She says her Buster Machine has a large scale degeneracy generator that can act as a fuse. Tashiro tells her to wait, but she doesn’t listen. Kazumi combines with Noriko and says that if they have two degeneracy generators, they can make it back to Earth. They enter Buster Machine #3 and descend into Jupiter, which is compressed to 1/30,000th its original size. Jung joins them in her Sizzler, but Noriko tells her it won’t withstand the pressure. Jung says she doesn’t care but Kazumi tells her they aren’t going to their deaths. Jung says it could take them centuries to return, but Noriko says they’re doing it so everyone else can live in the same time. Kazumi says that if she lives, tomorrow will always come. Noriko asks Jung to tell Kimiko that she’ll be back. Jung says that when they return, she’ll greet them with a big ‘Welcome back.’ As Gunbuster reaches the core, all communications are cut off. Noriko apologizes to Kazumi for dragging her into it, but Kazumi is fine so long as she’s with Noriko. Noriko rips out Buster Machine #1’s degeneracy generator and shoves it into the core. Buster Machine #3 activates and the Galactic Core Assault Fleet warps away. Jung tells Noriko and Kazumi to make sure they return. The Black Hole Bomb implodes and Gunbuster flies away. Noriko apologizes to Kimiko, saying she’ll never be able to see her again. On Earth, Kimiko thinks she hears Noriko calling out to her.
Twelve thousand years later, Gunbuster makes it back to Earth, but Noriko doesn’t see any lights. Kazumi wonders if they failed and humanity was destroyed after all. Suddenly, lights begin to come on and spell out WELCOME BACK. Noriko thanks Gunbuster and bids it farewell. Noriko and Kazumi head down to Earth.
For this movie, episodes 1-4 had a lot of their content cut out, episode 5 had very little cut out, and episode 6 was included in its entirety. The result is a good movie that contains the same elements that made the OVA great but it does stumble. Since so much was cut out the transitions are a bit rough in places and certain characters appear out of nowhere because their introductions were removed. Jung’s bonding with Noriko and Kazumi is gone, so her being so broken up at the end doesn’t work very well. Noriko only has two scenes with Smith before they partner up so her mentally speaking to him later in the movie also doesn’t work very well. Still, it works as a whole and I understand that they couldn’t animate new scenes for smoother transitions due to its age. A minor nitpick: the re-recorded audio lacks the same punch as the original, especially Noriko’s screaming. In the end it loses points because there is absolutely no reason to watch this over the OVA. Unless you really want to own the localized Blu-ray, just stick to the unabridged version.