This story tells of a man who was in the military. He was permanently and severely scarred as he watched all his friends die from a bomb explosion. Back home he considers his only choice to become a police officer. While wearing a badge, he gets a partner in the form of a police dog. He also has to change to find love, become a detective, solve crimes, teach the young and many more.
More specifically: The first book introduces Mars and his new partner Nitro. The second book brings in a love interest for Mars - The girl in the pink hair. The third book sees Mars and Nitro patrolling at the local shopping centre. The fourth book sees Mars finally getting his promotion to detective. The fifth book sees Mars and Nitro investigating burglaries on the trains. The sixth book - Mars and Nitro are loaned out to the school for a series of lectures. The seventh and final book sees Mars and Nitro receive a trainee… a newly minted trainee.