Kaneko, Sharon

Kaneko Sharon is an astronomer living in Japan. She shares a very close friendship with Mutta and Hibito, acting as their mentor. As children, Mutta and Hibito called her "Aunt Sharon." She taught them many things growing up and has given them many life lessons since then. The brothers still seek her advice to this day.

[Spoiler] In episode 64, she was diagnosed with amyotrophic lateral sclerosis (ALS), or Lou Gehrig's Disease. [/Spoiler]

(Source: Uchuu Kyoudai Wikia)