Rina san,
This is a hybrid- video is Chisato performing the song, but voice belongs to Mizugachi, who performed the fan dub.
I did see the Chisato version, but it got pulled very fast, didn't it? Truthfully, I never liked this song that much. Mizugachi, Chisato and Maki, all sing it well, but the song itself is ??? for me.