As with most of her serials, Watase planned the basic story line of Ceres through to the end before beginning work. She notes that it is easier to work this way, but that even with planning sometimes the characters will "move on their own" and refuse to follow her original plans. When she reaches the end of the work, though, she can understand why they did so. Watase noted that one of the hardest parts of writing a serial manga was having to plan for a cliffhanger at the end of each chapter. She wanted each one to make the reader want to know what happened next, so they would want to keep reading.