Description: The entrance level is the second level. When you get into the building, you'll see the elevator just in front of you. Take it and go to level M.
Leaving the elevator, you'll find the men washroom at your left. This is for employees of the restaurants mostly, but is all the time very quiet. Nobody really goes there, then it's very easy to have fun without being bothered.
There are two urinals and three big stalls. You can also use the men's washroom at the 3rd level (very quiet too, but the best is on level M).