Breaking Through the Enemy

(from ebookjapan):

The Japanese military has been betrayed by the Chinese, whom they hired as spies, and have stolen important military secrets! It is said to be hidden in six pieces of old coins.

A boy is sent on a mission to recover all the old coins before they fall into the hands of the Chinese government forces. However, he is under siege by enemies all around him! Will he be able to safely retrieve all the old coins...?!

Includes two stories, "Six Pieces of Ancient Coins" and "Battalion Annihilation".