In internet slang, "" is a corruption of "source," used to ask for the origin of a piece of media. The "animation 3" and "verified" components typically refer to high-quality or specific fan-made 3D projects:
A sound file circulating on 4chan's "/x/" board labeled y_sadako_sauce_aud.mp3 does contain static with a reversed counting rhythm. Using spectral analysis, we identified the underlying audio as a clip from Kaidan (1964) reversed and layered over a 3kHz hum. However, this audio is not attached to any verified video. It appears the sound is real, but the visual is missing. yamamura sadako sauce animation 3 verified
The biggest source of confusion is the word "Sauce." In internet slang, "sauce" means source (as in, "Please provide the sauce for that video"). However, non-English speakers—particularly in the Japanese and Brazilian meme communities—often literalize the slang. The Fascinating Story of Yamamura Sadako: Uncovering the