You're chasing a ghost. A 1971 music video by Mouri Atsushi, gone from every archive, survives only in the fact that people remember it existed. That's the entire cultural weight of this thing: proof that something beautiful was made and then erased.
Watashi no Kamifuusen is a single-episode music video from 1971. It presents the original version of the song, performed by Akai Tori, with animation by Mouri Atsushi. Neither the audio tape nor the video tape is known to survive, so the whole piece is regarded as lost media. Several factors contributed to its disappearance: the copyright rules of the period, the cost of film reels, and the practice of recording over old tapes.