Princess Principal tells the story of a team of high school girls and their exploits in espionage. The setting is 19th century Albion (England) and a cold war is being fought over territory and the mysterious substance Cavorite. From the name alone, you could be forgiven for believing the story to be a slice of life story about a princess going to school, but nothing could be further from the truth (a common theme in the show), and the first episode gives a perfect summary of what to expect from the whole series.
The first minute or so is used to establish the setting, which immediately dismisses any notion of this being a slice of life story, but this alone leaves a vacuum in meaning, as so far, there is nothing to suggest what the themes would be. It does drop hints that the show would discuss a parallel to East and West Germany, and nothing says "Cold War" louder than spy drama. Then the opening starts, with an excellent use of character emotion and scene design to communicate their personalities before any one of them speaks a word. The opening ends centered on 2 objects: roses, and some strange orb. The roses represent how these girls may appear cute, but trying to touch one is bound to get you hurt. The orb is simply a device used by the main character, Ange, to fly.
One of the first things shown once the episode starts is that this episode is Case 13. I don't particularly dislike shows that portray the plot in a nonlinear fashion. It allows the director to better control tonal transitions as well as giving us what spies themselves would see: An incomplete truth (the show only goes 12 episodes). Part of what I like about this episode is that, if you want, you can treat it like a standalone story which is complete and well told. There is also a great attention to detail from the very beginning. On a first viewing, Ange watching the defector, Eric from afar seems to just be her choice of securing a target. On a rewatch, it is easy enough to tell she is looking for anything suspicious about the man, as well as keeping track of him. Ange tells Eric an obvious lie, which seems to have no purpose, but it's really meant to let his guard down for when Ange tells much subtler lies later. All this detail is present in the first 4 minutes of the show; a true proof of its quality that even the show's detractors have to recognize. If you know what you are looking for, you can find a scene exactly 1 second long that gives a big hint to solving Ange's past.
What follows from the first scene is a simple introduction to the characters: both the main cast, and their spy command team. Their personalities are easy to deduce from the conversations, but what makes them unique is saved for the end. Ange continues to make Eric lower his guard by feeding him lie after lie, pretending to have tells. Then they go on a recon mission to investigate Eric's sister. Ange goes to her hospital room, changing disguises and stealing random medication she thinks will be useful, all while her sidekick Beatrice follows behind clumsily. After the visit to the hospital and the realization that Eric is after money, Ange knows most of the story, only half way to the episode's conclusion. Beatrice is completely unaware of the situation, but she leaves the strategy and planning to the rest of her team anyway.
After that, nothing is particularly remarkable until the climax; it's all necessary setup to describe the type of people who comprise the team and to prepare the payoff when Ange reveals the twist. Her suspicions of Eric's motives lead her to stake out Eric's window, which proves vital when they capture a pidgeon transporting a damning message. What follows is a great scene of two intelligence agencies working against each other simultaneously as one tries to use Eric as a lure, while Ange's team tries to stop them and address the threat Eric poses. The battle is extremely one sided as the supporting cast take over their opponents' headquarters, while Ange brings Eric to a faraway spot. He leaves the car and pulls a gun on Ange, now knowing his betrayal was discovered. Ange stays perfectly calm and tells him the gun is unloaded, dropping a few bullets onto the floor of the car to prove it. Once again, the attention to detail is perfect: The gun is an 8 shot revolver, but Ange only drops 4 bullets. She threatens him by insulting his spy ability and pulls out a contract for him to sign. Feeling defeated, Eric drops everything he holds as he walks over, thinking Ange is taking pity on him. Ange picks up the discarded gun and when asked if she is going to kill him, responds "no" 4 times; one for each shot she fires at him with his own gun.
I watched the show as it aired, and it was the only show where I ever watched the first episode twice before the rest of the series. The engaging story, along with the amazing attention to detail, all complemented by a Yuki Kajiura soundtrack makes this show a must-watch for any spy or thriller lovers. The action is plentiful while being sparse enough to be memorable. Every aspect of the first episode serves as a perfect introduction, while giving a glimpse at the promising story ahead. As such, when asked what anime series has the best opening episode, I would respond Princess Principal 10 times over. Then maybe Steins;Gate, but who's keeping track at this point?