The Rebel Army is being under attack by the Martians. The Professor (aka Chief), is urged to evacuate, though he is amazed by their technology and wishes to join them. Abigail appears and tries to take him to safety, but is distracted when she sees Donald Morden being abducted by a Dai-Manji. The Professor tries to seek an audience with Rootmars, but is denied by the Mars People Elite, who believe that humans destroy the environment and their technology is not high enough.
The Professor is beamed back down and encounters a common Mars People. He manages to communicate with it. The common Mars People tells him that Rootmars came to Earth as it wants to protect the environment that the humans are destroying, and that there are traces of technology advanced than theirs on Earth. One of these is the Sun Stone. It also reveals that the Professor can join if he can prove his strength to Rootmars. The Professor runs to the location of the Sun Stone, even though he is unaware of the powerful guardian protecting it.
The Martian tries to catch up to the Professor but gets lost, accidentally stumbling onto a group of Samurai soldiers. Later on, Allen O'Neil and Rebel Infantry arrive to capture the Professor, as he carries too much secrets to be let loose. Unfortunately for Allen, his soldiers get brainwashed by the Sol Dae Rokker, so he is unable to continue the pursuit. As the Professor makes his way, he is attacked by the brainwashed soldiers. The Martian arrives to protect him and starts to collect samples, much to the surprise of the Martian. The Professor explains that he is amazed by the brainwashing level of the Sol Dae Rokker, and asks why the Martian came as it is weaker than him. He also explains that researchers never give up and continue to reach the outcome of their work.
Sometime after this, more brainwashed soldiers, including one in LV Armor, attack the pair. The Martian protects the Professor with his life, which raises some concern. After the battle, the Professor realizes that the Martian is dead. Suddenly, two Mars People Elite teleport in to carry their fallen comrade away. The Professor tells them that he hasn't finished his test yet, so the Mars People Elite decide to stay with him. The Martian, believing that he is dead, is telepathically communicated by his fellow Mars People and Rootmars. He wanted to become an elite, but is unable to, and realizes that it is having a nightmare. At the end of the nightmare, he sees the Professor, who reminds him of a researcher's work and never gives up. This transforms the Martian into a Neo Martian, which surprises the Mars People Elite. The Professor is happy to see his friend and the two defeat the Sol Dae Rokker.
At the end of the battle, the Mars People Elite destroy the Sun Stone. They state that in the wrong hands, it could destroy the environment. They also reveal that the Professor has passed his test and can now join the Martians, which pleases him. The Professor asks for Marty (the Neo Martian) to accompany him. Marty is initially confused by his name, to which the Professor reveals that he is a bit annoyed by the fact that the Martians have no names, so he has decided to name them. Marty is happy to be alongside the Professor and accompanies him.
The Professor continues his experiments with Marty, who is surprised that humans can endure such conditions. Marty wishes to play with the other Martians and have fun. Elsewhere, Rootmars laughs, with the Mars People Elite translating his laughs. They say that they will continue to protect Earth's environment and punish humans that would try to harm it.
A Cadre Martian panics, as he cannot telepathically connect with the Neo Martian. The other Cadre Martian suggests to try singing as humans use it to apparently relieve stress. After singing, the panicking Martian calms and tells his comrade that the Neo Martian, Marty, is missing. This alerts both of them, so they consult with the Professor. The Professor is concerned for Marty's safety, but had a GPS on him. From the GPS, the Professor realizes that Marty has been kidnapped and the three move out to save him.
At the military instillation, the group is attacked by the Rebels. A pink alien then appears and tries to communicate with the Cadre Martians, though neither of them understand it. The Rebels attempt to apprehend Percier, the pink alien. After defeating the rebels, Percier tells the Professor that she will follow him as she is her "eternal assistant". They examine the equipment and Percier touches it, gaining energy. The Professor decides to bring Percier along as they can't leave her here.
Deeper in the lab, Marty is being drained of energy to power a Big Gate. Future Rebels appear and salute Morden. Elsewhere, the Cadre Martians detect Marty's presence and tell the Professor that something is preventing them from teleporting to him. The Professor asks Percier if someone else is researching Martians. Percier tells him that Navy took over after he left but was more interested in pharmaceuticals. The Professor decides to rush to Marty, but Percier advises him not to as he will most certainly die if they run into Allen. The Professor explains that Marty is his assistant and that the jamming device needs to be destroyed if it can stop Marty. Future Rebels then appear and ambush them.
Realizing that there are too much Future Rebels, the Professor realizes that the current Rebels have opened the Big Gate. He explains to the Martians that it allows the Future Rebels to enter into their world. Percier tells him that the Rebels have found out that the rarer the Martian, the more energy they can provide. Suddenly, Marty telepathically communicates with her.
Marty reveals that he is glad to make a new friend, though Percier shuns him as the Professor seemingly abandoned her. They find Marty, and one of the Cadres tries to take the tube off Marty. The Professor stops him as it is connected to Marty and forcibly removing it would hurt him. Percier is ready to pull the tube, but the Professor does it instead. Percier notices that Marty is calm when the Professor approached him. A cadre notes Marty's essence dissipating, and the Professor cuts the tube off, closing the gate. Percier also notices the Professor is showing a lot of emotion, to which he replies that he can't forgive the Rebel Army for this.
Outside, a Kraken is ready for deployment. The Professor notes that it is smaller than the Rugname, but has a lot of destructive power. Morden appears and taunts the Professor quickly analyzes for weaknesses, and concludes that the armor can only be damaged from the air with massive energy. Percier remembers that she has some residual energy and jumpstarts Marty by grabbing one of his tentacles. Marty grabs her before she collapses, though she is not impressed. Marty confronts the Kraken with his allies.
The Kraken is destroyed, though Marty collapses again and he has used all the energy. Morden laughs despite defiant odds, and the Professor warns him that he won't forgive the general for this before leaving. The Professor notices Percier blushing after Marty points at her and wondered when they became friends.
Percier asks the Professor if he needs anything. The Professor tells her that even with the costume, she can't replicate a Martian, though Percier notes that he has talked with her more often when she wears the costume. Marty wishes to accompany Percier but she refuses, telling him to go back to sleep since he's hurt. Marty refuses to step down and the two prepare to fight, with the Professor sighing and stating that if they're going to fight, they should do it outside.
What I need to be Myself
Nowan recalls an old memory where he was a large creature and eventually took the form of a humanoid it had befriended. Meanwhile, Odette is ready to head to Earth when "Annette" arrives. "Annette" tells Odette that they should not go to Earth and spend their time freely, to which Odette realizes that "Annette" is not real. "Annette" reverts to Nowan, who properly introduces itself to Odette, though Odette does not return the formalities as she dislikes being teased and insists on going alone.
Odette finally arrives on Earth, with Nowan in tow. Odette tells Nowan to stick to the mission, as they're here to search for an intelligent life being and to avoid conflict if possible. Nowan decides to have some fun and impersonates Allen O'Neil, entering the Rebel base. With few humans in the area, Nowan sheds his disguise and kills them. Nowan causes more havoc inside the base.
Putting back her Allen O'Neil form, Allen Jr. arrives and is ordered by Nowan to secure the armory while he chases the "enemies". Outside, Odette tells Nowan stop attracting attention. Nowan finds another hangar and enters, marveled by a train. Allen Jr. appears with several soldiers, shooting at Nowan. Nowan sheds his disguise and asks how he managed to find out he was fake. Allen Jr. responds that the laugh was wrong, as he missed a forth "ha" that his father was known for.
Nowan easily defeats the rebel soldiers, just as the real Allen O'Neil arrives. Nowan quickly disguises herself as Allen Jr., which prompts the real one to threaten him and confusing Allen O'Neil himself. To determine the fake, Allen O'Neil orders his son to drop his weapon. Nowan drops his weapon, causing Allen to restrain his real son. With Allen Jr. gone, he shoots Nowan. Allen O'Neil explains that his son would never put down his weapon when tensions are high, and that he'd reflect the bullets he shot at him. Nowan is apprehended by the rebels.
In a holding cell, Odette calls Nowan and tells him that he underestimated the humans. He cuts her off before she is able to do anything. Some time passes, and both father and son attempt to interrogate Nowan but fail. Allen O'Neil deduces that Nowan is not alone and that there must be more of his kind. Suddenly, a rebel soldier tells them that another alien is outside. Nowan realizes that Odette is coming to save him and warns her that it is a trap, but she comes anyways as she reminds him that he has no way to escape. Upon acquiring Nowan, Odette fights both Allens in order to escape. After a short scuffle, Odette is weakened and both of them are recaptured, while the rebels decide what to do with them. Odette reveals that she came to save him because he is her ally, and that help is coming.
The same day, Odette tells Nowan that Annette is coming for them. Nowan reminds her that it took them a significant amount of time to arrive, and that the humans are unlikely to keep them alive for that long. Allen Jr. enters the cell and tells them that Odette will be sent to the lab for experimentation. The next day, "Odette" is taken out of the cell and into the lab. Nowan recalls a memory with herself. Odette wakes up and realizes that Nowan is nowhere to be seen.
Arriving at the experimentation room, the proceedings are interrupted when the base is attacked. Annette arrives and is relieved to see "Odette", but quickly realizes that it is Nowan instead. Allen Jr. orders the soldiers to deploy the Emain Machas. At the end of the battle, the twins are destroyed. Annette and Nowan rush to the building where Odette is being held in. A soldier asks Allen Jr. if they should pursue them, which he declines as he wants to keep the losses minimum and that they've got plenty of samples from the battle.
Odette thanks Annette for saving her, and asks how she arrived so fast. Annette tells her that she followed them as soon as they left, as she believed something would happen during her mission to Earth. Nowan asks Annette how she knew he wasn't Odette, and that his mimicry skills are the best in the army. Annette replies that while he had the appearance and voice of Odette, he lacked something which distinguished between the two. At the rebel lab, Navy is delighted with the alien samples, as they're equal to Neo Martians. Vita arrives and Navy tasks her to deliver the samples to Morden.
Back on the Invader homeworld, Nowan and Odette look at shooting stars. Annette appears and gives Odette a schedule, reminding her that relaxation is over and that it's time to return to Earth. It is revealed that Annette and Odette are actually sisters. Annette tells Nowan that it is a secret because she didn't want to look like she was spoiling Odette due to her carefree personality. She tells him not to let anyone else know of this secret.