In the near future, a large meteor strikes Japan on what is now being called "Dark Sunday" and completely destroys the country. With the help of the US and China, Japan was able to construct New Tokyo, which has 50m walls built around it to protect the city from the contamination outside. With crime rates rocketing, the New Tokyo Police Squad was formed to bring peace to the new city. Rachael is the top field operative who has solved countless cases and captured or killed countless criminals. However, she refuses to take a partner after her old partner was murdered. But Rachael soon finds herself working with Mizutani Asuka, a young girl newly recruited by the police squad, and, to her surprise, Asuka is a better marksman and has superior combat skills to Rachael. That’s a given though, since her new partner is an android.