Katsuji Chinen, principal of Futenma No. 2 Elementary School in Ginowan, Okinawa Prefecture, stands on its rooftop on Dec. 11. The U.S. Marine Corps Air Station Futenma can be seen behind an evacuation center on the schoolyard. (Amane Shimazaki) GINOWAN, Okinawa Prefecture--Katsuji Chinen was deeply disturbed by the sight of elementary school pupils kicking around a ball without a care in the world. Chinen, the principal of Futenma No. 2 Elementary School, was in his office in early December when he heard the familiar buzzing of an approaching helicopter from the nearby U.S. Marine Corps Air Station Futenma. The noise became so loud that he could no longer hear the voices of the 10 or so children who continued playing in the schoolyard.