Uchuu Kyodai is one of the few mangas that can motivate my live, read this is more like reading graphic biography than reading manga.
The story tell us about an older brother named Nanba Mutta who want to become an astronout to follow his younger brother path, Nanba Hibito. I think the synopsis was enough to describe the main plot. The story develops every new characters are introduced but still focus on Mutta reaching his dream.
Like my word before, this is more like biography than manga because the characters more like real person than fictional character. Our older brother Mutta is 31 years old in first chapter while the other stories have main character in his/her teenage. Same with the other character that their age, jobs, and background is like real person. The environment seems real too even make me thing maybe the mangaka is real japanese astronout.
I think the strongest part of this manga is the story itself, the best mood builder. It can make me laugh, smile, and sad (but not cry). I can feel Mutta's feeling for his brother between happy and envy at the same time or I can feel his feeling when his path is closer to the space little by little. This is why this manga can motivate my live.
Conclusion : I recommend Uchuu Kyodai to everyone who loved realistic story, have a dream, a man who have younger brother, and (maybe) want to become astronout. There is no bad thing to try this, maybe you want to watch the anime first is okay too since it already covers many chapters, read or watch and feel it yourself.
