The setting for Night Raid 1931 is 1930s China, a tumultuous period when the Imperial Japanese army was occupying parts of mainland China. The story follows a small group of Japanese in Shanghai, ostensibly civilians, but in reality an independent group of spies working for the Japanese government. They take on some of the shadowy activities that official government operatives can't be involved in.
And these aren't just any spies, but spies with superpowers: teleportation, psionics, speed. The exact source of the powers isn't really specified. I got the impression that they came either from mutations or mystical spirits, but it doesn't really matter. The powers are important, but they aren't the central focus of the story...more of a supporting role.
The characters themselves are a big part of what makes Night Raid 1931 work so well. Each character is well defined and has their own motivations. The telepathic girl hunting for her missing older brother. The tight-laced young military man unsure of which side is in the right. The older man in charge of the team's missions, using his mysterious contacts to set up their activities. I found myself wishing the series was a bit longer to explore their backgrounds a bit more, and find out what happens to some of them in the future.
The historical setting is very much in the center of the storyline. Freedom for Asian countries from the colonial powers is a major theme. The Manchurian Incident is a major turning point. The distrust and strife between Japanese and Chinese during this period is made very clear in several instances. I ended up doing some reading up on the period when the show made a reference to something I wasn't familiar with, and what I found fit very nicely into how the story was progressing. The writers clearly know the period and did their best to make things fit.
That's not to say that this is a historical drama. Beside the obvious difference of people with superpowers, the entire plot revolves around a secret organization that isn't in the historical record, and their efforts to change the course of history. By the end, it isn't clear whether the story is meant to take place in our own history, showing us secret events that have been forgotten; or if it's all in a parallel reality, that has its own future that may not be like our own. It didn't really matter to me which it was, because either way it was a well-executed story that kept me interested all the way through.
In the end, my only complaint about Night Raid 1931 is that there wasn't enough of it. For anyone who enjoys a bit of a mystery, set in an interesting historical period that isn't commonly used, and doesn't mind suspending disbelief in the occasional use of superpowers - highly recommended!
