Voiced by: Natsuko Kuwatani (Japanese), Rebecca Forstadt (English), Nana Mizuki (early drama CD)

The third Rozen Maiden doll, and Souseiseki's older twin. She and Souseiseki are both referred to as "gardeners" for their ability to communicate and tend not only to regular plants, but also to the "soul trees" of humans.

Despite her attitude towards Jun, Suiseiseki does care a great deal for him, and her attempts to cover that up usually manifest in the form of more insults. In fact, she cares deeply for everyone in her life, even if she does not show it outwardly, a personality of a stereotypical tsundere. In Rozen Maiden träumend, Suiseiseki stands out among the dolls in that she values her sisters' love more than the goal of becoming Alice. She is one of the few dolls who opposes the Alice Game, and has no intentions of becoming Alice if it means taking her fellow sisters' Rosa Mystica. Suiseiseki and Jun attempt, without much success, to convince the other Rozen Maidens that the Alice Game is a meaningless endeavor. In her brief appearance in the OVA, she makes the same appeal to her twin several times.

In the anime, Suiseiseki's first impression is different than that of the manga. She appears very shy and nervous, and is very distrustful of humans because one had kidnapped Souseiseki. Shinku once described Suiseiseki as being the most shy and timid of the Rozen Maidens. She also tends to end nearly every sentence with "desu", as a way of being polite. This has made her one of the more well-known characters in the series.

Suiseiseki tries to avoid participating in the Alice Game as much as possible, but she can use her watering can to make plants emerge from the ground and manipulate them. Her artificial spirit is named after the popular Anna Sui perfume. Suiseiseki was also the winner of the Anime Saimoe Tournament in 2006.

In Rozen Maiden Träumend, Jun becomes her medium (after trying to find a medium on her own with no success). She is shown to be jealous of Shinku, because Jun's attention is always directed towards her. This means she also cares about Jun.

In the next-to-last episode of Rozen Maiden träumend, Suiseiseki attempts to protect Kanaria from Barasuishou's crystal stakes, and is crystallized for her trouble and her Rosa Mystica seized. Suiseiseki was revived by Rozen in the träumend finale and is last seen watching "Detective Kun Kun" along with Nori and the lifeless forms of Souseiseki and Hinaichigo.

In the latest chapters of the manga, Suiseiseki makes a return to the story as she travels to the alternate dimension where Shinku and Suigintou currently reside. Knowing that Kirakishou now has Souseiseki's body, Suiseiseki intends to protect Kirakishou from being destroyed, much to Shinku's and Suigintou's dismays. She has also actively (and somewhat forcibly) made Jun form a contract with her. However, she was actually making him form a contract using Souseiseki's ring, so that Souseiseki may be revived. Yet, though Souseiseki was able to break free of Kirakishou's control, she lacks her Rosa Mystica, which Suigintou currently has, and refuses to return. In the end, Suiseiseki gives her Rosa Mystica to Souseiseki. To return to their world, Souseiseki convinces Suigintou to return the Rosa Mystica to their rightful owners, Suigintou agrees, allowing Suiseiseki to come back to life. Together, they restore order to the worlds.