Cocoon  

Cocoon: Aru Natsu no Shoujo-tachi yori, cocoon ～ある夏の少女たちより～

Two girls named San and Mayu were students in Okinawa at the end of World War II. They were part of a group of classmates who were conscripted into nursing wounded soldiers as part of their war effort. When they were ordered to sacrifice themselves for their country, only a few of them managed to escape. They then had to deal with the harsh conditions of their tropical paradise that had turned into a war zone.