Timelapse can be faked as well. See how some directors in mainstream movies do fake One Shots. I'm sure there are girls who are willing to do anything for money, so I can't be 100% sure of course. However, in porn, many things are staged for convenience purpose. Sometimes, it's very obvious if the director is lazy, sometimes it's more well done
You make really good points, I've seen quite a few badly done fake ones. Either jump cuts, laminar flow piss (plastic pipe) or obvious changes in the color/amount piss or cum. Totally ruined the immersion for me
(I know JAV is mostly fake).
In this video however, there is a 4 second window when the camera zooms in and the bowl is out of frame (when I assume the bowl could be replaced), it is on screen with no cuts the entire time otherwise.
I analyzed the video before and after the off screen segment by visual feature matching, this should indicate whether they replaced bowl or not. In the picture I uploaded, I matched a distinct piss splash pattern and a scratch on the bowl. It is difficult to make out whether the scratch is just a reflection in the uploaded still photos, but if you watch the video, it is quite obvious both are not just reflections and are in the same place. The piss splash matches perfectly and is pretty distinct. The color and amount of piss also says the same. Hence, I am very confident they did not replace the bowl.
Another way I can think of to fake it would be remote controlled rubber penises for the men (they are naked and have both hands in frame so probably not). The penises also twitch due to muscle contractions when they are squeezing out the last bit of piss, so probably no fake penises.
The only other way would be if the men got fake piss injected up their urethra before shooting. You never know what the Japanese are capable off.
Given there are plenty of other scenes (in this video and others) where this actress is drinking tons of piss, either directly or large bowls, I think this piss drinking scene is probably real. Thanks for your contribution though,