Story
Friendship is the key to protecting the world. That is everyone's wish. Here in a world where science has solved all questions. This story is set in Oshima. The happy, carefree 14 year old Akane Isshiki lived a poor, but well loved life together with her reliable little sister, Momo, who does all the housework, and her grandfather, Kenjirou, a genius inventor who only created useless devices. When the weather is clear, they can see the artificial island, Blue Island, across the sea.
Synopsis via AniList (English).