Reddit mentions of Janissaries (Janissaries series Book 1)

The Janissaries by Jerry Pournelle

While anime doesn't have anything like that which is done well, there is a book series called Janissaries which is exactly that. It's about a group of US mercenaries who were cut off and left for dead before being rescued by an alien race and taken to a planet where they would use guns and what he learned in school as far as science(such as introducing black powder and modern tactics) to subjugate the local people and then grow a mysterious crop for the aliens, or that was the plan at least. The books protoganist is a college dropout and leader of the mercs who suffers a mutiny as soon as he gets put on planet. Now he must use his wits and military know-how to lead the local populace and figure out exactly why this planet full of humans exists and what plans the aliens have once they get the desired harvest. The most interesting thing is not only is the author a veteran scifi writer but he also holds a masters degree in psychology from university of Washington and a PhD in political science from the same school. I like it because while it is a scifi novel, none of the actions of the characters or events that play out actually seem illogical.

https://www.amazon.com/Janissaries-Book-1-Jerry-Pournelle-ebook/dp/B00APARD0K