I think most of you have seen this kind of hair style in some history textbooks. This is a Japanese traditional hair style for men, called "Chonmage." This hair style was common 400 years ago as many Japanese soldiers called samurai had it.
Recently, this hair style can be seen only from sumo wrestlers because this hair style was prohibited by Japanese government when a foreign country (the United States) forced Japan to open and have trade with other countries. Then Japan began to become more westernized and this traditional hair style disappeared in our society nowadays. (However, now hair style is not limited by the government, so you can try Chonmage if you want)