This is the ninth arrangement of the album. Artist: ARM (イオシス) Song: ｳｯｰｳｯｰｳﾏｳﾏ(ﾟ∀ﾟ) (Which I believe is Caramelldansen despite not knowing Japanese) Romaji: U-u-umauma(ﾟ∀ﾟ)
To answer your description, yeah, the Japanese version has the lyrics "U-u-uma-uma." They write it that way in the video, but I'm not sure if they ever sing in Japanese, so they never actually sing it.
It's a Japanese remix of a Swedish song. While this song is Swedish it's very popular in Japan due to having some J-Pop elements in it and anime girls dancing in the video.
You could probably get the acapella if you are able to get a hold of the instrumental and use that to help you get it by telling whatever software you're using to isolate the song into only having the vocals.
