The story unfolds around one particular question: what if rainbows were actually men and women from the future who had come to observe the past? Ten-year-old Arco lives in the distant future of 2932. During his first flight, dressed in his rainbow space suit, he goes off course and ends up in the past of 2075. Iris, a little girl his age, sees him fall from the sky. She takes him in and helps him to get back home in any way she can…