Luka

is a Japanese light novel series written by Hirotaka Nanae, with illustrations by Hiroshi Mishima. The series began publication on February 10, 2005 by ASCII Media Works under their Dengeki Bunko publishing imprint.

The series won the Grand Prize in the 11th Dengeki Novel Prize.

Synopsis
What if the world is destroyed? What if the family is fake? What if I was the last person in the world? The girl lived in a "box garden" with a family of five and an old dog, Toppy. Surrounded by the smiles and kindness of the whole family, I am having a very happy life. ――But that happiness was false. A world where humanity has perished.

The story of a lonely girl who survived alone.