The Flowers of War

Nanjing, December 1937. An American (Christian Bale) hides inside a church with a bunch of frightened school children from maurading Japanese soldiers who are burning the city to the ground. They're soon joined in the church by a dozen seductive courtesans.

Because the Japanese won't harm Westerners, the man is convinced by the women to pose as a priest in order to protect the children from certain death or worse.