Sasami, Ayeka's younger sister is also a princess of Jurai. Although she is the youngest of the royal descendants, she is the most powerful, and commands Tsunami, a Jurai ship with incredible capabilities.

In the second OVA series, Sasami reveals a secret about herself. When she was much younger, she suffered a near-fatal accident. To save her life, Tsunami assimilated with her, meaning that they are now closely connected. Therefore, Sasami will resemble Tsunami when she grows up (a fact that Ryoko and Ayeka are none too pleased about, since they believe Tsunami is far prettier than either of them!).

Her chronological age of 708/709 (in the OVA series only) is due to the fact that she accompanied her sister on her 700-year mission to find Yosho. As with Ayeka, this event does not occur in the TV series.

Her full name in the OVA series is Sasami Masaki Jurai, being a descendant of the Masaki house, one of the four royal houses of Jurai that are descended directly from the first emperor of Jurai. The genealogy of the Juraian royal family is significantly different in the other TV series' continuities, and is not explored to any great depth.