Both of them died of cardiac arrest.
One is a boy (17~18) ,third grade of the high school. There is no school lunch. He did not play sports hard. He was just studying for the entrance exam of university. He called in sick on 11/29/2011 ,and died the next day.
The other one was a girl (16~17) ,second grade of the high school. She naturally had a heart problem.Her heart was smaller than usual. However ,there was no limit in her daily life. She was a cheerleader at her last sport fest. 2 days later ,she died.
The school is in west Tokyo. No more details are announced.