I have noted that "Making good stairs is an important part of green design; you want people to use them instead of elevators in bigger buildings, and you want to get tighter, more efficient plans in smaller ones." Now, just after reporting that Japanese houses are weird, here's one that isn't particularly, and that has a very interesting stair.
Most of the really minimalist cantilevered designs like this one look simple, but there is a lot of engineering going on behind the plaster to hold it up. Kenji Ido's design for a stair in a house in Osaka (see it all on Arch Daily) is almost as minimal as the single tread cantilever, but by making it a box of two treads, it has a depth that puts far less stress on the connection to the wall. It becomes minimal in its material use as well as its appearance. That's clever design.