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.

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.

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

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

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.

Hibito begins the test that will determine if he can return to active duty. However, Chief Butler has planned a surprise for Hibito.

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