Yes, the safespot works on all difficulties.
You can sit in many places around Sakuya, but I think her right side is the most commonly used.
Basically you want to sit as close to her as possible without hitting her.
You have to be fairly precise.
I use the lines of the hexagon as a guide: the green spot is where your hitbox should be.
![](http://i44.tinypic.com/6p94ow.png)
Keep in mind you only have around 1 second to position yourself, so it is a difficult one to pull off.
Plus, she moves during that 1 second to the top center of the screen, so you may have to adjust accordingly.