Sleepy student in Japan

I found interesting article on the Asahi Shimbun (It’s a newspaper like New York Time). It said that …
The research shows that 73.3% of High school student in Japan doze or are asleep or blank while they are in class. Moreover, more than 50% of them sleep past midnight.
On the other hands, American high school students who often sleep in classes or are blank are 48.5% and, doing same question in China, there are 28.8%. Both in America and Chine, high school students sleep around 10p.m ~11p.m and this is the most common bedtime hour while only 10% of Japanese go to bed at that period of time.
By the research, they don’t keep awake for studying. According to another article (Ellen’s blog http://www.ellenseflblog.blogspot.com/) they are sending E-mail to their friends or spending their time in convenience stores.
I don’t entirely agree these opinions. I know that many of them keep awake for sending E-mail, or watching TV. But there is another type. Are there really nobody studying at night?? I think 50% of awaking student in Japan is studying past midnight. I think they eager to sleep much early time, but they can’t. Because of the system of Japanese University’s entrance examination, it would be more and more difficult.
As you know, Japanese University is very difficult to enroll while graduation at there is easy. Some student would think that they just go to the University where they are able to enter. But others wouldn’t think so. To enter top University like Tokyo University, Waseda or Keio means confirmative security to enter Fortune 500 companies. As proof of this aspect, if you go to human resources at Tokyo Marine and Fire Insurance Company, Limited in recruiting time, placard says
“Please hand in the application in the right box if you are Tokyo University’s, Waseda University’s or Keio University’s student or alumna (alumna means people who graduate the university)”. And the placard says, too “Please hand in the application in the left box if you are the other university student’s or alumna.”
Don’t you think that it’s injustice? So students who want to enter top company have to study hard. Therefore, Japanese high school students are so tired out their study and go to Juku (cram school). We have too many things to do in spit of being exhausted.