In addition to the constitution
excerpt, there is no provision currently for
women to succeed the throne, as ruling
Empress. There have been
Japanese empresses that have ruled
Japan directly or behind the scenes, though they have been few.
The constitution itself is somewhat vague over the position and powers of the Emperor. Though he seems to mostly be a figurehead, he has a great deal of respect from the Japanese people, which also extends to the armed forces, the Japanese Self-defense forces. This gives him a far higher degree of support than one would expect.
After WWII, the Allied forces wanted to ensure that the Emperor would not have nearly as much power as he did before. Though this is disputed by some, they believed he had a great hand in the war and its atrocities. There were even movements to make Japan a Republic. Such ideas were dropped, when it was pointed out that such actions would probably spark an incredibly violent uprising.
Though support for the monarchy is more moderate today in Japan, a piece of paper cannot outline the feelings and respect that an entire nation holds toward its head of state.