I love how Ayu distances herself from her subject matter in many of her PVs. She acts as the muse, a sympathetic spectator, commenting on what she sees but unable to affect the world. Notice how only the other girls have direct interaction with the men, how she blinks in and out when the men aren't there, how she sits atop that chair fiddling with the white stuff while the girls get totally washed by it, and especially how she blinks in at the end and looks contemplative.
So my first interpretation was that it's semen because of the prostitute motif. However, I felt compelled to search for another interpretation because I wondered if Ayu would use such a symbol. I noticed that the same white stuff flows down over the nostalgic anime scenes, which have white backgrounds. I think a strong interpretation can be that the white fluid erasing the anime memories is flowing into real life and erasing it too. I think it can represent the overwhelming force (which many posters have discussed in this thread) of the relationship which destroys "the good times we had together." The white stuff in the anime scenes' context adds a third possible identity, the background color of the animation washing it out. Perhaps the white color of the fluid in the real life shots is designed to be a reference to the animation.
Was that chocolate in Moments? I totally thought that was dark blood. It looked like she was a dying angel...
