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.

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.

After learning that his former boss has told JAXA about the headbutt incident, Mutta has given up hope on passing the exam. To cope, Mutta falls back on his childhood habit of multitasking like crazy when something bad happens.

When the robber known as the fire extinguisher man strikes the restaurant where Mutta is, he's in trouble. But once the dust settles, Mutta has become a national hero for capturing the criminal. However, it appears there's more to the story.

After five days in their sealed boxes, each team is exhibiting a pronounced personality. Mutta's Team A is rowdy, while Team C is quiet. However, Kenji's Team B appears to be a little gloomy.

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

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.