Main characters reminiscing about their past.

When Jun buys Shinku a brooch, she refuses to accept it at all costs. Souseiseki then confronts Jun with the reason for Shinku's behavior. The tragic story of Suigintou is told, with the revelation of why her hatred for Shinku could last throughout centuries. 

Note: This OVA has some spoilers of Rozen Maiden: Träumend, the second season of Rozen Maiden. These episodes fall chronologically between the 5th and 6th episodes of Rozen Maiden: Träumend, but might spoil later revelations.

On Filiel's 15th birthday, she received her mother&rsquo;s necklace as a memento from her obstinate astronomer father. Her common and tedious life was turned into a life of conspiracies. With her new life, many adventures await.
 
(Source: Anime News Network)

Aizawa Ryota was in the 3rd grade of the preparatory course of Central Military Academy. AD 2045, he went to a space station, Aries, for the training with his classmates including Nagase Saka and Nittak Kazuhiko. However, the station was attacked by a terrorist group, Hallarax.Now they must find a way back to earth.
 
(Source: Anime News Network)

In a Japan not quite like our own, the "youkai" (supernatural creatures) have started living together with humans. Now, in an ordinary school, all sorts of "monsters" attend regular classes. A human boy, Oohashi Shingo, finds himself attracted to one of these creatures, a "petopeto" called Fujimura Hatoko. Petoko, as she is called, is a minor monster, with only the power to stick to something she adores. Like Shingo....
 
(Source: Anime News Network)

Aizawa Ayumu is a young boy, who is sent to a small town called Tana to live with his father for a while. Even though he doesn't want to go, he agrees to do so when his mother offers him a mountain bike. Ayumu used to live in Tana before, and now his memories of the time are shrouded in mystery - apparently something happened when he was a child. Enter Miku, a young girl who knows more than she tells, weird glowing lights floating around, reflections of UFOish objects in the eyes of cats and dogs, a nosy female announcer, a forest with a mysterious past, and a weird boy called Wakkun, who wears the clothes Ayumu used to when he was a child, and you get the world of Zettai Shonen, where mysteries remain mysteries amidst a slow, normal, everyday life.
 
(Source: Anime News Network)

As summer break arrives for the students, Jun Sakurada is busily studying on his own in the library, making up for time lost while he had confined himself to his home. Meanwhile, his Rozen Maiden doll, Shinku, has been having troubling dreams of late. The pain and sadness of defeating Suigintou was overwhelming, despite the inevitable battle they waged. After waking suddenly from a nightmare, she finds Suigintou's companion spirit wandering; upon giving chase, she discovers that the seventh Doll-- Barasuishou-- has awakened. She now realizes that Suigintou's fate may very well befall the other Dolls, for the appearance of the last Doll signals the beginning of the end of the Alice Games.
 
(Source: Anime News Network)

Sakurada Jun spends his days online, ordering whatever he takes a liking to, only to return it before the payment is due. Due to psychological trauma from school, Jun generally keeps contact with people as little as possible. One day he finds instructions online that tell him to put his order into his desk drawer. Rubbing it off as a joke, Jun mindlessly does so only to find that his order instantly disappears from his drawer. A package suddenly appears, containing a beautiful antique doll. When wound up, this doll comes to life. Sadly for Jun, this doll Shinku views Jun as an equivalent for a servant. Despite the constant demands Jun now receives from Shinku, she slowly helps him overcome his fears of human contact as well as protect him from the deadly battles that come into his life due to her appearance.

Mellow Head