Uchuu Kyoudai: Itten no Hikari
Japanese title: プラネタリウム 宇宙兄弟 ～一点のひかり～
Alternative titles: Space Brothers, Planetarium Uchuu Kyoudai
Type: Movie
Source: Original
Episodes: 1
Status: Finished Airing
Aired: Jul 21, 2012
Duration: 38 min
Rating: PG-13 - Teens 13 or older
Studios: A-1 Pictures
Producers: Digital Media Lab
Genres: Comedy, Sci-Fi, Slice of Life

The anime's original story features Mutta and Hibito during one summer when they were children. During the summer when Mutta and Hibito made their promise to go to space, they met a young girl who also had a wish.

(Source: ANN)