What is Sakura Taisen?
Sakura Taisen or Sakura Wars is a video game franchise developed by Red Company and published by Sega Enterprises. It is a historical Steam Punk series with some Fantasy World Elements (Demons/Spiritual Powers). It started with the first Game Sakura Taisen in 1996. Since then the franchise has expanded to include anime, manga live musical performances, arcade games and even it's own cafe an specialty store. Sakura Taisen has truly become a multimedia phenomenon inside Japan and also has a strong fan following in the US.
The intro the the PS2 Remake of the first game Atsuki Chishio Ni, uploaded by jpmeyer

This truck is an example of the steam powered devices that can be found in Sakura Taisen
The story is one with romance, drama and culture set in an altered 1920s (Taisho) Era world. The world is a very different place thanks to the invasions made by horrific demons called Kouma. This has caused a rapid increase in the technological level of society but this technology is still based on the principles of the Steam age; cars, aircraft and high speed bullet trains all powered by steam. The political rivalries of the real world, have been mostly put aside as mankind tries to struggle with the threats looming in the darkness. It is a prosperous world, with little racial intolerance, compared to our society at the time, it is the world of Sakura Taisen.
The Teikoku Kagekidan
The Hana-gumi and Kaze-gumi
Most Sakura Taisen products revolve around the girls of the Teikoku Kagekidan, or Imperial Operetta Troupe, an all female musical revue; this troupe was inspired by two sources the Takarazuka Kagekidan and the Shochiku Kagekidan both all female revues started in the 1920s. In the Sakura Taisen series, the fictitious Operetta is the cover for the secret Imperial Assault Troupe; this is based on a clever pun the kanji for both read exactly the same way Teikoku Kagekidan. The girls of the assault troupe are chosen for their possession of high levels of spiritual power, which allows them to pilot the Koubu spirit amour as well as manifest some psychic abilities. High levels of spiritual power is found usually only in young women and only a few male examples are seen throughout the series (notably series protagonists Oogami Ichrou and Taiga Shinjirou).
The Teikoku Kagekidan is divided into different troupes or gumi, each of whom, serve a different role in both the running of the theatre and in combat. The different troupes are: Hana(Flower)-Gumi, Kaze(Wind)-Gumi, Hoshi(Star)-Gumi, Tsuki(Moon)-Gumi, Yume(Dream)-Gumi and the Bara(Rose)-Gumi; the troupe division system is based on the Takarazuka Revue. The Hana-gumi uses the stylish Great Imperial Theatre, based on the Shochiku Kagekidan's theatre, in Ginza as it's base of operations.
Paris and New York Kagekidans


Left the Paris group in Street clothes right the New York group in revue outfits
As the series expanded future sequel games and OVAs were set in Paris and New York, this is most likely a nod to the fact that the Kagekidan style of theatre was a fusion of traditional Japanese theatre, Parisian Dance Revue and Broadway Musicals. Like their Japanese counter parts the Paris and New York teams masquerade as all female performance troupes based out of the Le Chattes Noirs a Parisian night club/cabaret and the Little Lips theatre an up scale Broadway venue located on time's square.
The Games

The Game's famous LIPS (Live Interactive
Picture System) interface
The games are Dramatic Adventure games in which you control the main character Oogami Ichirou (and later Taiga Shinjirou) and lead the Kagekidan troupes into battle. Throughout the course of the game you will go through the day to day operations of the theatre and life in the bustling metropolis, and interact with the female Koubu pilots developing a romantic relationship with one or another. The games are a fusion of dating sim, and tactical rpg; they are divided into episodes creating a larger story arc the effect is that of a simulated anime television series where you control the actions of the main character. Each episode is fairly linear having only one or maybe two final outcomes (with the exception of date episodes where there is a different version for each heroine), but they have a very open story path where you can wander around and participate in many different events, and discover hidden scenes. In addition to the 5 main games in the series their is a plethora of additional side games and software spread across the different systems. Sakura Taisen 1 and 2 were on the Sega Saturn, 3 and 4 on the Dreamcast all console games since have been on the Playstation 2.
Anime/Manga
To date there have been 5 Sakura Taisen OVAs, One movie and one TV series. The OVAs and movie fill the gaps between the games or are character studies of existing characters. The TV series was a slightly darker remake of the first game, but it had a wildly altered storyline and is not cannon. The manga runs in the Japanese Monthly Magazine Z and is published in English by Tokyopop, it is a faithful and expanded retelling of the first game. Monthly Magazine Z also runs 4 panel humorous Sakura Taisen strips and a manga poking fun at Sakura Taisen fandom.
Live Performances (Kayou Shows)
The Kayou Shows are live performances where the Sakura Taisen Voice Actors or Seiyuu reprise their roles on stage; there were two main shows every year: the Super Kayou Show in the summer and the Shinshun Show in the winter, with various other performances throughout the year. The Super Kayou Shows had a unique format where one act would be a story about the Hana-gumi and the second act would be a play preformed by them.