One is a light blue Arabic numeral 1, being particularly based off the design of a "1" with a base (𝟷), most likely taken from the original Minesweeper. A quirk regarding her design is that the diagonal part and base of the "1" are misaligned, the diagonal part appearing more far off to the left, the degree to this varying between scenes. One's blue coloring is similar to that of Four's, albeit slightly more pastel. She is armless.