U.S. Marines lead a foot patrol during Forest Light 15-1 at the Oyanohara Training Area in Yamato, Kumamoto prefecture, Japan Dec. 9. Forest Light is a routine, semi-annual exercise designed to enhance the U.S. and Japan military partnership, solidify regional security agreements and improve individual and unit-level skills. The Marines are with 2nd Battalion, 9th Marine Regiment, currently attached to 4th Marine Regiment, 3rd Marine Division, III Marine Expeditionary Force, under the unit deployment program. - U.S. Marines lead a foot patrol during Forest Light 15-1 at the Oyanohara Training Area in Yamato, Kumamoto prefecture, Japan Dec. 9. Forest Light is a routine, semi-annual exercise designed to enhance the U.S. and Japan military partnership, solidify regional security agreements and improve individual and unit-level skills. The Marines are with 2nd Battalion, 9th Marine Regiment, currently attached to 4th Marine Regiment, 3rd Marine Division, III Marine Expeditionary Force, under the unit deployment program.