The year 2006. Two brothers, Nanba Mutta (age 12) and Hibito (age 9), happen to spot a UFO headed for the moon. The experience inspires them to make a certain promise.

With his mother's assistance and Hibito's encouragement, Mutta has been accepted for the New Astronaut Selection Exam. However, unsure of his next step, he visits Sharon, who works at a nearby observatory. After receiving advice from Sharon, Mutta is finally able to make up his mind.

After advancing to the second exam, Mutta realizes that the other applicants are much better prepared than he is. Desperate to prove himself, he stakes everything on the lung capacity test, as he has confidence in his trumpet-trained lungs. However, as the other applicants drop out, he finds himself in a heated battle with Itou Serika. Who will come out on top?

Hibito's disappearance is distracting Mutta during training and he makes a critical mistake. What will Hibito do next, and will Mutta be able to get his act together before the actual launch?

After a long week, only the final interview remains in the second JAXA exam. Mutta is drawing attention as Nanba Hibito's older brother, but he insists he won't spend his entire life as Nanba Hibito's big brother.

It's their final day in the sealed box. Mutta has enjoyed his two weeks with the team, and he wishes to avert ruining their bond, as they make their final decision.

The teams have two days left in the sealed boxes. Mission Control has deliberately not given certain members of Kenji's Team B any green cards, leading to paranoia. Meanwhile, in Team A, Mutta announces that he has good news, bad news, and dicey news.

It's New Year's, and the Nanba family is together in Houston to celebrate. Mutta feels good, as he trains for the moon and talks to Serika, but Hibito doesn't seem to be in a celebratory mood.

Mutta has arrived in America, but he's off to a rocky start with Hibito. Meanwhile, his future as an astronaut is in jeopardy because the headbutt incident has been brought to JAXA's attention.

After completing the second JAXA exam, Hibito invites Mutta for a free trip to Houston, Texas, through NASA's family support program. Upon arrival, he finds himself chased by a pug named Apo, and is then reunited with Hibito. However, Hibito expresses disappointment.

Mutta and Kenji have overcome their initial shock after hearing that only one of them will be chosen to go to the moon. Now that they're working together again, everything seems to be going right with their construction of the Moonbase.

Mutta and Hibito are selected for a magazine cover. Mutta is excited, but he notices that Hibito is acting strangely.

Mutta and Nitta backtrack through the desert, looking for Nitta's cell phone. But Nitta cannot find it in time to answer his little brother's call. Has he lost another chance to reach him?

The astronaut candidates continue their survival training in the desert. Team E has fallen behind the others, but after Nitta takes the lead, they try to pick up the pace.

Troubled by Hibito's disappearance, Mutta's performance begins slipping. However, a conversation with Chief Butler reassures him.

Mutta has returned from his training in the desert and gets some rest as Christmas approaches. Meanwhile, Kenji and Nitta finally learn about the mission they've been assigned to.

Mutta has been assigned to the CES-62 backup crew, but his fellow members aren't keen to work together. Will the arrival of Eddie Jay, their leader, turn things around?

Mutta comes up with an idea to prevent vehicular accidents on the moon. Will NASA accept his proposal?

Hibito struggles with the panic disorder that's afflicted him since his ordeal on the moon. However, he requests that his condition be kept secret from Mutta, who may have found a way to improve the lunar rover.

After Mutta takes a make-up exam, this time managing to concentrate properly, he once again meets Deneil Young. With the top scoring AsCans being assigned to the best flight instructors for their T-38 training, Mutta, as the only one who had to take a make-up, is assigned to Deneil.

As Azuma makes his way towards the moon, Mutta's team works on testing the rover, learning of what flaws they need to fix. The team consider following another team's example and going with a glider instead of a ground rover, but Pico points out that the wind would cause issues with that plan. Using his engineer insight on how to overcome their obstacles, Mutta suggests that they make the rover's tires out of sponge, so they can have larger tires that still fit inside the rocket whilst also reducing costs and providing shock absorption. Impressed by this idea, Pico decides to give the team advice on their parachute, encouraging them to think of the rover as a spaceship containing their comrades. With Mutta's ideas and Pico's advice, the team manage to put together a working rover complete with a functioning parachute. Later, as Mutta is invited by Pico for a drink, Vince takes him for a drive.

The third astronaut selection exam has finally ended. Team A used rock-paper-scissors to select two members. Whose dreams are still alive?

The fifteen remaining candidates have been divided into three teams of five. Each team will spend two weeks inside a sealed box, while completing various tasks. The first task is to determine the time.

The third exam will take two weeks. Mutta and the other candidates are transported via sealed bus to a large, barren facility. Then they are led to an area that is known as the last room.

As Sharon makes a new proposal to NASA for the lunar telescope, Mutta continues his training in the desert. However, Chief Butler is still seeking a backup captain for the mission.

As the survival training draws to a close, Nitta suddenly tells the team he needs to backtrack due to losing his cell phone, but Mutta stops him. However, Mutta appears to have an idea in mind.

Two hours have passed since JAXA was supposed to notify the candidates, and Mutta hasn't received a call. When the phone finally rings, he's told to go to a nearby park. What will his fate be?

With the third exam finally over, Furuya takes the opportunity to visit the man who made his dream possible.

Mutta has learned that Kenji and Serika have strong reasons to become astronauts, while Mutta is simply trying to achieve a childhood dream. This causes Mutta to begin to question himself.

Mutta's proposal to add a windshield to the lunar rover is received well. However, Chief Butler is still reluctant to allow Mutta to train for lunar missions. Mutta decides he must try something more dramatic.

While Mutta waits to hear if he will become an astronaut, Kenji has received good news. The next candidate to get a call is Serika.

The final exam is set to take place in two months. Mutta heads to Houston, ahead of the other candidates to look after Apo and tour the Johnson Space Center. Meanwhile, Hibito is training hard for his lunar mission.

Pico and Vince were pushed by their fathers and teachers to apply for their local technical college, which angered Rick, who felt betrayed by the others for giving up their dreams. Before they could make up with each other, Rick died in a car accident on the day Pico and Vince attended a career day for the mines. Distraught and angered by Rick's death, Pico and Vince reaffirmed their resolve to pursue careers as astronauts, as life is too short for unexciting things. Back in the present, Azuma and his group arrive at the moon base, where he reunites with Hibito, who thanks him for helping to save his life, whilst Mutta, Kenji and Nitta watch it on TV. As the day of the Comeback Competition arrives, Pico informs Mutta and Kenji that a rainfall the previous night could potentially cause huge problems with the sponge tires, the worst case scenario given them only an hour to do something about it.

With a limited amount of time before they launch, the team search for materials they can use to keep the sponge tires dry. Visiting the hotel's utility room, Mutta borrows some silicone sealant from the janitor, which he uses to waterproof the tires. With all their elements in place, along with Mutta's addition of a toy astronaut to represent the purpose of the experiment, the rover manages to make it 200m from the target goal before its battery dies, ranking them fifth overall and second amongst the AsCans. After the contest, they are approach by the winning team, whose director turns out to be none other than Naoto, who is working hard to develop a Japanese manned rocket.

As Hibito, along with Damian and Linda, begin their journey back to Earth, Mutta's group give Pico their rover as a memento of their time together. The day soon comes for the space module Orion to enter the atmosphere and a collective sigh of relief is heard as the parachutes are successfully deployed and the three astronauts land safely. Arriving in Houston, Hibito greets Mutta, giving him a piece of rock from the moon as a souvenir.

Whilst Hibito, Damian and Linda begin their rehabiliation, Amanti tells Mutta about a premonition she had about him, saying someone close to him will soon be stricken by a serious illness. Meanwhile, Sharon travels to a conference in America to propose the construction of a lunar telescope. Back in Houston, Mutta and the other AsCans are at Ellington Airport where they much learn how to pilot a T-38 jet as part of their astronaut training. Mutta is called up by Sharon who, after talking with Serika who is a big fan of hers, says she will be in Houston in two days, whilst Mutta starts to worry if she is the one Amanti mentioned.

With the final astronaut selection exam coming up, Mutta heads to Houston. However, Jennifer has some ominous news.

Two days are left before launch. First, the lunar lander Artemis goes into space on Mars V. Afterwards, Hibito and the rest of the crew will head into space on Mars I.

As Mutta and his teammates try to keep warm in the cold desert night, Mutta is reminded of recent events.

The JAXA astronaut candidates head to Houston, to begin training at NASA. However, Murakami-san appears to have a surprise in store for Mutta.

Mutta and the other astronaut candidates have arrived in Houston to begin training at NASA. First up is a social event to meet the other astronaut candidates from around the world.

Hibito continues to struggle in rehab. Russian astronaut Ivan Tolstoy shows Hibito videos of his daughter as a child, learning ballet. Will the videos give Hibito his answer?

It's finally the day of the launch, but the weather doesn't look good. On top of that, Apo's run off, so Mutta has to go find him. While searching for Apo, Mutta comes across a suspicious old man.

Hibito and the CES-51 crew have landed on the moon. Meanwhile, Mutta has returned to Japan to await his final exam results. He's especially concerned about using up his luck before the results are announced.

Mutta has begun his life as an astronaut. First, he must undergo a month of JAXA training and orientation. Meanwhile, Hibito and Damian head out in a lunar rover to track down a missing probe.

The AsCans begin their flight studies, in which they must learn three weeks worth of flight knowledge in three days. Meanwhile, Sharon speaks with Daniel Morrison, a university lecturer from Hawaii, who expresses his interest in her telescope proposal and offers his support. She eventually arrives in Houston where she meets up with Hibito, who senses some limpness in her hands. After Sharon falls over whilst trying to carry some drinks, her assistant and Hibito check her into a medical center, where the doctor claims she is only feeling fatigue. Later that night, Hibito and Sharon head to a party Mutta and the others are holding. When Serika notices Sharon's battered cellphone, she is reminded of when her father was first diagnosed with his illness and discovers Sharon is showing the same symptons he had.

Mutta's flight training is progressing well. Meanwhile, Hibito heads back to Japan, where he is greeted by cheering g crowds and parades. He also gets a chance to visit Sharon.

After Mutta completes flight training, he officially becomes an astronaut. Now he must wait to see if he will be assigned to a lunar mission.

After completing training, Mutta is offered a spot on the backup crew for an upcoming ISS mission. This is a golden opportunity for Mutta to make it to space quickly. But he must consider what he truly wants to do.

Mutta and the other astronaut candidates have finally finished their Japanese training. Before they head to Houston, they receive a gift from Director Nasuda.

NASA and JAXA have decided to bring Hibito back to Houston, placing him in a supporting role. Hibito has no choice but to pack up and make his farewells.

Seven days remain before Hibito takes off on a journey to become the first Japanese person to walk on the moon. Meanwhile, Mutta prepares for the final astronaut selection exam at Johnson Space Center.

JAXA has begun announcing the results of the final astronaut selection exam. Makabe Kenji receives the first phone call. As Kenji waits to learn his fate, he reflects on his motivation for wanting to be an astronaut.

Oxygen generation system Brian arrives just in time to save Hibito. Once he and Damian are rescued and back at Moonbase, he reflects on the astronauts who saved him.

The third exam is halfway over. Mutta works on a completely white puzzle as he ponders why Fukuda-san would break the only clock in the sealed box.

Deneil takes Mutta on his first T-38 flight where, unlike the other instructors, he flies at speeds of 6.5Gs. Mutta throws up on his first flight, though after hearing Hibito went through the same training, he decides to go on it again. He soon begins training to fly himself, tasked with relying on instruments instead of sight. Whilst intially having trouble, Mutta is soon encouraged by Deneil's advice and Sharon's hand written letter, encouraging him to train for what he can.

Mutta has convinced Chief Butler to allow him to start training for lunar missions. Meanwhile, Hibito is in Russia, trying to overcome his panic disorder.

Hibito has returned to Houston from Russia. At the same time, Mutta begins his journey to the moon with NEEMO training.

Mutta's idea for improving the lunar rover has earned him the right to participate in NEEMO training. He has taken one step toward the moon.

The third exam inside the sealed boxes has been underway for ten days. Each team has been experiencing unexpected problems, such as broken clocks and mysterious alarms that ring in the middle of the night. However, Mutta soon realizes who is actually responsible.