The anime revolves around a creator of dolls created a legendary collection of 7 living dolls, called "Rozen Maiden", he puts them in a game, in order to know which doll is worthy of becoming "Alice" the perfect girl. The story follows Jun, a hikikimori which has a school trauma and accidentally becomes master of the fifth doll, Shinku.
The anime has a melancholy and mysterious air, this can be seen mainly in the opening of the anime and in his scenarios. It has a very interesting story and endearing characters.
Something very interesting in this anime is that the author did a story with a boy as protagonist surrounded dolls, breaking the stereotype that only girls should be involved with dolls without this seems strange. It's that kind of anime that even when not focused on the plot can arrest you with comic situations.
It is not very faithful to the manga, and unfortunately the features of some characters have been modified: Shinku in the manga is not as serious as this anime, the same thing with Suigintou doll, which in the manga makes many sarcastic jokes, but in the anime is more serious. The Jun sister also makes many jokes about puberty, but in the anime it is virtually nonexistent. Even with these differences, the anime still manages to get the main ideas of the plot.
During the anime we can see the evolution of the protagonist in relation to their trauma, and even over the characters, like his sister and dolls, in which he did not get along very well.
The only thing I think was missing in anime, that was not much talked about the creator of Rozen Maiden, nor how he did it and what were his exact reasons for this. In the manga it has been said more clearly, but in the anime it has gone a bit unnoticed.
If you are looking for something different, with comedy and a bit of drama, Rozen Maiden is a good choice.
