Why did SNSD translate some of their songs to Japanese?

hmmm!!! i think thats why most of their songs translated into japanese ver. so that the japanese people who also idolized snsd can really understand and so that if they will have a show, concerto in Japão they can sing their songs por translating it into japanese version.... ahm, i think thats all... ::)))

It's because they are promoting in Japão as well as Korea now. When you promote música in another country, it's only logical to be cantar it in that country's language. And, they probably redid Gee and Genie because they were so popular.