PCDOS

PC-DOS is essentially MS-DOS-tan's twin sister, as they were both released during the era of IBM / Microsoft cooperation. While both still harbor an unconscious yearning to be reunited, time and distance have diverged their personalities, PC-DOS now being more mature but a tad ill-tempered and a workaholic. Even their clothes are similar, although PC-DOS-tan's skirt bears the IBM colors and she carries an IBM ThinkPad as opposed to MS-DOS-tan's keyboard.

See also:

• List of OS-tans