Shinku is the fifth Rozen Maiden doll and the first to appear in the series. She embodies the traditional Victorian aristocrat. Her favorite words are "tea", "servant" and "What?" She regularly and nonchalantly delivers physical punishment to Jun, her medium, and in her own eyes, her servant. She sees it as her duty not only to discipline Jun as her servant, but also to guide him as a guardian. Shinku may seem cold and unappreciative, but she is highly protective of and cares deeply for her sisters and for Jun. She can be relied on for the occasional bit of parent-like wisdom. Despite her aristocratic quirks, Shinku is the most level-headed doll living in Jun's house.

However, her one weakness is her fear of imperfection; a fear that is powerful enough to shatter her normally cool demeanor. Father put so much effort into her that she feels an obsessive need to become Alice. In her eyes, the Alice Game is cruel, and she is reluctant to take the souls of her sisters, leaving them as the lifeless "junk" they fear more than anything else.

Shinku does not use honorific suffixes such as "-chan," "-san," or "-kun," except when she refers to "Father." Despite her relative youth amongst the Rozen Maidens, the other dolls look up to her as an older sister, and a worthy challenger in the Alice Game. Shinku does have a cute side, which is evident in her intense, almost obsessive, admiration for the puppet detective Kun Kun. Jun was once able to win her over during an argument by using a Kun Kun doll. Shinku hates cats because one almost ate her wind-up key in the past.

Along with being the central doll in the series, Shinku seems to hold a special place in "Father"'s heart; he had given her a special brooch with his image when she was created, which Suigintou destroyed out of jealousy. Shinku desires to become "Alice," but she refuses to use deadly force against her sisters and believes that there must be a way to become Alice without taking part in the Alice Game as told to her by "Father".

In combat, Shinku fights with rose petal-based attacks, making her one of the strongest dolls in battle. The rose petals are extremely versatile; Shinku can direct them to spread out for wide-ranging attacks, or group them together to use as a shield. Her other weapon is a cane, which she skillfully wields like a sword. Shinku has other special powers, such as restoring broken objects, typically Jun's bedroom windows after Suiseiseki and Souseiseki show up, with a form of time-reversing magic. Shinku was the second runner-up for both Saimoe 2005 and 2007.

Medium: Jun (All Seasons)/Sara (In 19th Century)

Artificial Spirit: Hollie (Called Hollier in Tokyopop translation.)

Shinku's name in English means "True Crimson".