This explains the green hair and lack of familiarity with common items. She spent a lot of time star-watching on the starship she came here on, and assumes (in the Yotsuba & Stars chapter) that the brightest star in the sky is Earth because that's what it used to be when she was going here. * Then the last chapter would be about her real parents coming back to get her. ;_; * ...But then Yotsuba decides, in the end, to stay on Earth, because, after all, "Earth is best after all, right?".