Story
Two brothers looked to the starry skies as children and made a promise ... Now, in the year 2025, the younger brother, Hibito, is carrying his out. He is an astronaut who has been selected as a crew member for mankind’s first long-term base on the moon. Meanwhile, the older brother, Mutta, has just been fired from his job and is unemployed, but decides to trust himself just one last time.
Synopsis via AniList (English).
Preview
From the anime adaptation: Space Brothers.