A second Dark Age has fallen upon the world. Human civilization has been reduced to scattered tribes and tiny villages, just barely hanging on in a harsh environment. The only exception is the city of Oasis, it's fortress walls protecting those fortunate enough to survive the trip through the open desert. The city was created by "The New Goddesses" not only as a haven from the dangers of a barbaric land, but also in hopes of starting the world anew.

Most people travel to Hawaii to escape from the craziness of their lives for a while, but from the moment Yumei arrived at the airport, she knew this was no vacation. Klutzy assassins, philanthropist bullies, and even the landscape itself seem to be out to get her. What's your typical ninja girl supposed to do?