Copy-pasta:
The UST belongs to sango312.
The singers are:
Kaen Shujoteki - Mario
Kasui Kamene - Bowser
Hotaru Utami - Peach (I need more girl UTAUloids)
Cecile Rail - Luigi
I didn't add a video BG or subtitles. I felt lazy. And converting the video just made things go out of whack. D: