Chiisana Kuni no Kyuseishu 4 Shakariki Yuusha no Maki

is the fourth volume of the Chiisana Kuni no Kyuseishu light novel series, written by Kazuyaki Takami and Illustrated by Himeaki. It was released under the Dengeki Bunko Imprint in March 2007.

Synopsis
It's been a year since that civil war. Tatsuya stepped on Celica again to keep her promise to take Princess Ruka to Japan. Contrary to the smile of Princess Ryuka who greeted me, the domestic situation was in a state of immediate urgency due to the discord created between the government and the Nagas tribe, a leading tribe!

(source: Bookwalker JP - Translated)