In the summer of 2006, Mutta Nanba and his younger brother, Hibito, witness what they believe to be a UFO, which flies off towards the Moon.

As Mutta eventually recalls his past ambitions, he receives a letter stating he has been accepted to join a JAXA training program for new astronauts.

Space Brothers, written and illustrated by Chūya Koyama, has been serialized in Kodansha's Morning since December 6, 2007.

[6] The manga is available in digital form in North America and Europe from ComiXology and Amazon in both volume and SimulPub chapter format.

[17] The adaptation was written by Chuya Koyama and directed by Yoshitaka Mori, with Shun Oguri and Masaki Okada playing the roles of Mutta and Hibito respectively.

The theme song for the film is British alternative rock band Coldplay's "Every Teardrop Is a Waterfall" from their album Mylo Xyloto.

[26] In 2024, alongside Case Closed, Space Brothers won the grand prize of Rakuten Kobo's second E-book Award in the "Long Seller Comic" category.