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 コンサート in 日本 they can sing their songs によって translating it into japanese version.... ahm, i think thats all... ::)))
It's because they are promoting in 日本 as well as Korea now. When あなた promote 音楽 in another country, it's only logical to be 歌う it in that country's language. And, they probably redid Gee and Genie because they were so popular.