The previous Rozen Maiden animes were made very early when the manga was being written, so after a few episodes they changed to an original story (because they didn't have any more material to work with, but had to give the anime an ending).

So basically this is an all-new anime where you don't need to watch the other seasons because they don't follow up..

Also, liking this older Jun. C: (By the way, I didn't read the manga, so I'm very curious what the story will be like this time)