There is no Royal Familitchi. You're getting two models mixed up.
FamiTama = Japanese-language version of the V5 (other than language, the two are almost the same)
V5 Familitchi = Australian / Hong Kong / Singapore / USA / Canada / European version of the FamiTama
Royal FamiTama = Japanese-language model similar to the FamiTama but with different characters, different built-in games, and different foods & items
V5 Celebrity Familitchi = USA / Canada model similar to the Royal FamiTama, but has more built-in games (6 instead of 4) and some different foods & items
V5.5 Familitchi = Australian / Hong Kong / Singapore version of the V5 Celebrity