It is amazing how the traditional Japanese room has really stayed the same through the centuries. The overall concept of keeping true to natural materials of wood and the tatami mat remain consistent. Shape and form play an important role, always striving to allow for as much natural light as possible, while keeping to symmetry for balance and minimalism. Yet, only a few modern technologies have been implemented in the basic tatami room.
The traditional tatami room had only one light in the center of the ceiling, therefore, the shoji doors were often an important element to increase natural light. As you can see from the photo below, one whole wall uses shoji to not only divide the space, but to allow as much light in the main room. Notice the use of the upper shoji, that is ornamental as well as functional.
In this modern tatami room, the lighting is now recessed and they do not use shoji on the sliding doors. The windows are also very narrow and symmetrical. This may be due to privacy issues. Many homes in the city are built with very little space between each other leaving home owners with views of concrete walls and pedestrians. Therefore, it becomes important to understand that window placement becomes an important issue for privacy as well as natural light.
The following photo has a twist on the tatami, as it does not have the dark binding. In addition to this change, it uses two different tones of straw giving the mats a checkered yet unified appearance. Personally, I think the room looks much larger without the dark tatami binding. Now notice how they have used a dark wood instead of the usual light colored wood for the hallway, giving it a big contrast. This works for this situation because the room is much larger than the average room, especially with the addition of the modern sliding windows which have a full opening without posts to the back garden.
These empty rooms allow one to focus on the simple structure of the space and most importantly the guests and people who are present.
Images from http://blog.osakazine.net