The DS system released in November 2004. Miis initially started out as a test on the DS, perhaps a prototype of Tomodachi Collection. However, Miis would not make their debut until the Wii two years later. The DS doesn't actually support any Mii data formats itself, but a handful of games released on the system developed by Nintendo were unique in having Mii support. These games support the Wii-format (to transfer from the Wii's Mii Channel to the DS game cartridge), and introduced the DS-format, which is similar to the Wii-format but with the endianness swapped.