Suigintou is the first doll of the Rozen Maiden collection. Her desire to win the Alice Game is the strongest of all the dolls, and is primarily driven by her wish to gain the attention of "Father" (Rozen). Sadistic, spiteful, and arrogant (all due to her spectacular Superiority complex), Suigintou has no inhibitions when it comes to the Alice Game. She will use any method available to her, regardless of how brutal they may be, to grasp victory. Although she generally avoids associating with the other dolls on a social level, she has a particularly strong hate for Shinku. This hate borders on obsession, as she can approximate how many hours and minutes since they have last met. However, upon meeting Megu, her medium, Suigintou's attitude and motivations begin to shift; she begins to feel a strong affection for someone other than "Father". Suigintou's desire to protect Megu begins to even overpower her wish to meet him: she hopes to use the collected Rosa Mystica to heal Megu of her heart ailment, rather than become Alice. Suigintou has a number of unique traits and flaws amongst the seven Rozen Maiden. In the anime, she is missing her torso; Shinku explains at one point that before Suigintou was completed, her design was erased, but gives no further explanation as to why or how. Curiously, after Suigintou is destroyed in battle by Shinku partly she is restored mid-way through Rozen Maiden Träumend. The identity of the person responsible for her restoration is never revealed. In the Rozen Maiden Träumend finale, she tells Shinku that "Father" had told her that even with her flawed body, she was also entitled to a part in the Alice Game. Later, Rozen is seen lovingly fixing her neck ribbon as she is unconscious. He even grips gently around the waist afterwards, implying that he has mended her incomplete body.
In the manga, her body is flawed by wings (she is the only Rozen Maiden with them) that have ravaged her back with cracks. Despite these flaws, her love for "Father" and willpower is so strong that she can use her powers independently of a medium. Initially, Suigintou's will to exist was so strong that she was able to move without actually possessing a Rosa Mystica. Suigintou did not consciously make a contract with Megu, rather, Megu came upon Suigintou as she was reawakening. Suigintou's strong sense of independence, as well as disdain towards humanity, kept her avoiding having a medium. She is also the only Rozen Maiden to have been defeated and revived three times. In Rozen Maiden Ouvertüre, her complete past is revealed. Her intense hatred for Shinku stems from the very moment of Suigintou's awakening, when she notices Rozen affixing a brooch with his image on Shinku's bow. Nevertheless, they still managed to be friends as Suigintou was ignorant of the Rozen Maidens' true purpose--destruction of one another through the Alice Game--when they meet in 19th century London. Suigintou stumbles through a mirror in the room of Shinku's medium, wailing hysterically for "Father". Shinku takes Suigintou in after determining that she is not a threat. Shinku not only teaches her how to walk, but also treats her as an equal. One day, she follows Shinku into an Alice Game battle with Souseiseki, and is cut in half by Souseiseki's shears. This reveals her incomplete body, and she vanishes into a watery N-Field where "Father" gives her a Rosa Mystica of her own at last, thus, making Suigintou a true Rozen Maiden. Not long after, Shinku admits that she only felt pity for the "poor, unfinished doll" that certainly couldn't become Alice and insinuates that Suigintou could not possibly be a Rozen Maiden because she is flawed and different from all the others. This angers Suigintou, and she releases her black wings for the first time, beginning an Alice Game battle with Shinku. She eventually pulls Rozen's brooch from Shinku's ribbon and crushes it in front of her eyes. As Suigintou laughs arrogantly at Shinku's anguish, Shinku calls her "junk" which acts as the reason she refers to the other dolls as "junk" (particularly Shinku) and why she greatly resents being called it herself. The fight between the two becomes even more intense, but Laplace no Ma ends the battle, stating that the Alice Game of that era has ended.Along with her artificial spirit, Meimei, Suigintou's weapons are her ragged black wings. With their arrow-like feathers, she can conjure up a shield, a large sword, or even twin black dragons. Suigintou can also create destructive blue flames as a last resort in battle. The variety in Suigintou's abilities, particularly when combined with her savagely cunning nature, make her a strong player in the Alice Game. It is noted that "Mei" in Japanese means darkness. Medium: None (First Season)/Megu (Second Season) Suigintou's name in English means, "Mercury Lamp".