Watase purposefully left Ceres' true nature ambiguous in the end, never clearly stating whether Ceres is an alien or truly a being descended from heaven. She notes, however, that part of the reason for this was that it wasn't something she'd thought about. On reflection, she felt Ceres was a symbol. In Japan, men are considered the dominant sex, and Watase notes that as a woman there are things about the system that anger her, such as men saying she is "just a woman." "Ceres" became a story about the relationship between men and women. She also wanted to show that while the "Tennin" and the humans in the story may have come from different origins, and evolved differently, they were still the same living creature in the end, with similar feelings and thoughts.