Rozen Maiden AliBat: Record of Rozen War

Jun Sakurada, a pubescent hikikomori (severe recluse) likes to order things online, use them, the send them back before he has to pay for them. One day he takes up the offer to get a doll by placing a note in his desk. Much to his surprise, it comes and it has a mind of its own. His doll introduces herself as Shinku, the fifth Rozen Maiden. She bosses him around a lot and uses him as an energy medium via a ring called a Rosa Mystica so she can fight her 6 other sisters, all of which who want to become “Alice”, the perfect girl envisioned by their creator/father Rozen, but only one can survive. They’ve been alive several hundred years and intend to keep going until one remains.