How to animate sex scenes like in Sex Note?

[sunday322]

Does anyone know what program they used? or how the process is made

 

[lobotomist]

seems like traditional frame by frame animation

 

[shabadu]

While some of the earlier animations may have been frame-by-frame, I'm about 95% sure most of it is now done with some kind of sprite/2D rigging system. It's a relatively common technique these days and there's a bunch of different programs that can do it. The most famous is probably Live2D, but it could just as well be Spine, Spriter, DragonBones, random Adobe product, or even Blender. Heck, I think some game engines even have native support for it too.

Just google for something like "2d bone animation" and that should be a good starting point.