What Otaku Senshi AreIt is unclear where or when the term 'otaku senshi' originated, however it has become commonplace in the online Sailor Moon Community. The word 'otaku' is a Japanese word literally meaning 'house.' Generally, it is used as an insult or put-down in Japanese culture; an 'otaku' is a fan so devoted to one thing or another (most often, anime and manga) that they don't even get out of their house. Westerners have adopted the term 'otaku,' and while some still see it as an insult, many westerners have embraced it as a badge of honor for their devotion to anime and manga. You can read more in depth information about it in this Wikipedia article.
A Sailor Senshi is a character in the metaseries Pretty Soldier Sailor Moon with special powers used to fight and protect against evil (generally speaking). Usually female (see 'Male Senshi' in Conflicts section of this page), they use magical attacks and wear a certain style outfit often referred to as a 'sailor fuku.' 'Fuku' is the Japanese word for outfit, and the sailor fuku is one style of school uniforms seen historically in Japan. The sailor fuku that the Sailor Senshi wear was designed by Naoko Takeuchi, the creator of Sailor Moon, to be similar to the school uniform so that young girls could relate to her characters. It was her editor that suggested the connection between young school girls and these super hero outfits.
Following the example set by Naoko, otaku senshi are therefore fan-made sailor senshi. They are also sometimes called 'OCs' which stands for 'Original Characters'. Their creation often includes images, profiles, stories (called 'fanfiction') and RPGs (role-playing games). Otaku senshi are created by regular fans, like you!
The otaku senshi community is a very big one, full of many different types of people and characters. It is a community sustained by respect and support. We share our creations with one another to enhance the experience of Sailor Moon fans all over the world! Please see the Etiquette section for more information about what it means to belong to a community.
What Otaku Senshi Are NOT
Otaku senshi are not characters that appear in canon, or the original Sailor Moon story even though some otaku senshi might take the form of powered-up versions of existing Sailor Moon characters, or even canon characters that have become sailor senshi. Otaku senshi will often have detailed histories that tie their past into the Sailor Moon metaverse. This allows the character to seem more 'real' concerning canon.
(Canon, by the way, is the 'original' version of the story. Sailor Moon has two main canons: the anime and the manga. The musicals and live action series can also seen as their own canon respectively. Basicaly, anything 'canon' is something that exists in an 'official' version of the story.)
Otaku senshi are not (or at least should not) be copies of the canon characters of the original story. The goal for most otaku senshi creators is to make a unique and interesting character that expands upon Naoko's wonderful idea of a sailor senshi and explores the possibilities of the universe she created.
Contrary to what you might have read elsewhere, otaku senshi are not infringements on copyright. Their visual design and profiles are not violations of copyright because they are derivative works. Please see the Legalities section for more information about copyrights and otaku senshi. Most importantly - Naoko Takeuchi, the creator of Sailor Moon, has expressed her affection for fan created characters and stories.