Animal Forest (Animal Crossing) was originally being developed for the Nintendo 64DD by Takashi Tezuka
and his select team. As a result of the 64DD's extended delays, it was instead released on the Nintendo 64 as a standalone cartridge with a controller pack used to store all the data. The Japan-only Nintendo 64 edition of Animal Forest became a hit in Japan.
Due to its success and release at the end of the N64's lifespan, Nintendo decided to port over the game to the Nintendo GameCube. While Japan got a slightly improved Animal Forest +, America got the more meaty Animal Crossing the next year.
The scale of translating the initial Japanese version of Animal Crossing to English was immense. It took six months total. In an interview with N-Sider, the translators reflected back on all the work that went into the project. They had to translate thousands of lines of text, create new holidays, new items, and more -- which ultimately made Animal Crossing Nintendo of America's largest translation project to date.
Nintendo Japan was so impressed with the translation (new holidays, new furniture, etc.) of Animal Crossing by Nintendo of America's Treehouse division that they decided to translate NOA's version of Animal Crossing back into Japanese and release it as Doubutsu no Mori e-Plus. Doubutsu no Mori e-Plus sold 91,658 copies during its first week of sale in Japan.