Let's say each can of soda is 350g heavy. Times 4 that would be 1,4kg. That again is a force around 13,75N. If the radius of a can is 3.3cm, the pressure on Mugi's head is equal to 4044,11Pa.

Which is about the same pressure as a child of 13kg sitting on her head.

Yet she's sleeping like a baby. Impressive, Mugi.

They could be empty.

Considering that there are 3 more cans (if not more), I really hope they are empty.

...I'll just sit here and enjoy the moe show.

Well Mugi has been able to tolerate things better than the others.

Amazing head balance right there. Proves that she is indeed a true Ojou-sama.

Even "under pressure" she looks like an angel.

Under such a deep dream, I'd rather reach her and steal a kiss, even if her friends are not comfortable with the idea.