Kabuki, one of Japan's traditional entertainments, originated in the 17th century. It was developed by merchants during Edo Era as a way to express their emotions. Please refer to Kabuki: A Brief History, for more about its history.
Although many women played female roles in early times, the Tokugawa Shogun banned appearance of women in Kabuki plays in the early 17th century. As a result, all female roles are played by male actors called Onna-gata and the beauty of the Onna-gata became one of the most distinctive features in Kabuki performances. You can see the pictures of how male actors make themselves up to look like women..
Part of the excitement of watching Kabuki comes from the audience. During a play, the audience shouts the names of actors during short pauses. The timing of the shout must be just right. It's an interesting phenomena. Other interesting things to notice during Kabuki are the colorful and gorgeous costumes and make-up which the actors wear. Also, you might want to pay attention to how the stage (butai) is equipped. When shifting scenes in a play, the stage revolves. This is called Mawari-butai and is one of the famous characteristics of Kabuki theater.
You will also see people dressed all in black on the stage. They are called Kuroko, and their jobs are to take care of props and actors. When they appears on the stage, the audience is supposed to treat them as invisible. Also, the traditional Japanese music that accompanies Kabuki performances might interests you. The musicians rotate in and out of sight on the stage, which carries them.
Most of all Kabuki plays were written during 17th-18th century, so the language is hard to understand, even for Japanese people. In the Kabuki-za theater, you can buy English programs or rent earphones with which you can listen to the explanations of shows in English.
There are about 300 plays in the conventional kabuki repertoire. If you want to learn more about Kabuki play, go to Facts of Japanese Kabuki. This site explains the categories of kabuki plays. To see Kabuki online, visit Online theater. This page includes video of recent plays and illustrations.