Ryoko Balta (リョーコ・バルタ Ryōko Baruta?) is a fictional character in the Tenchi Muyo! spinoff series: Tenchi Muyo! GXP: Galaxy Police Transporter.
Although she named herself after Ryoko Hakubi, Ryoko Balta is hardly as bloodthirsty as that infamous space pirate was rumored to be. Even though she was a member of the dreaded Daluma pirate guild, Ryoko Balta is the most educated and cultured pirate there was. She is well-versed in many customs from other planets, including the Japanese Tea Ceremony. And her beauty is such that some male Galaxy Police members would be willing to desert their posts in order to join her (it is rumored that there are many "Ryoko Balta Fan Clubs" in some G.P. posts).
Within the pirate guild, however, Ryoko had few friends, and was hostile to Tarant Shank, the guild's vilest member. However, she is also a great friend of another of the guild's members, Kyo Komachi.
Ryoko Balta is also a shape-shifter, and she often used this power to infiltrate Galaxy Police posts to gain information. One of her favorite forms is that of Erma, a Wau Galaxy Police clerk who works for Airi Masaki, the head of the G.P.'s Jurai office and the grandmother of Tenchi Masaki.
Ryoko Balta first met Seina Yamada when her ship attacked the transport carrying him to the Galaxy Police Academy. Three of the crew - Alan, Barry and Cohen - forced a surrender when they found out Ryoko was on board. However, when she met Seina, Ryoko was taken in with him and allowed the transport to leave. She even deliberately failed to add Seina's name in the Daluma Guild's enemies list.
Shank forced Ryoko to participate in a plan of his by imprisoning the families of her crew and threatened to kill them unless she killed Seina Yamada. Using her disguise as Erma, Ryoko accompanied Seina on a shopping trip at the G.P. Academy. But when she finally confronted Seina, the boy gave her a present - a simple star pendant.
Overcome with guilt and shame, Ryoko dropped her disguise and confessed to Seina. She then turned the gun she planned to use to kill Seina on herself. But before she could pull the trigger, Amane Kaunaq and Kiriko Masaki (who were following Ryoko and Seina to keep an eye on them) barged in and stopped her. Ryoko was later captured by Airi; it seemed that a short time ago, Airi found out that Erma was really Ryoko but didn't have the evidence to prove it.
At the same time, Kyo Komachi (with secret help from Airi Masaki) managed to free the families of Ryoko's crew. At the same time, the families took with them a second-generation Juraian tree-seed, which the Daluma Guild had procured in the hopes of discovering its secrets
However, as per procedure, Ryoko Balta's DNA was listed in the Galaxy Police's database, and in the process, it was discovered that her DNA was disguised. The reason for this was that, in fact, she was the last heir to the Balta Guild, which stands to become a member of the Galactic Union. With help from Seto, she was released as a subordinate of Seina. After the group made it to Jurai, Seto revealed Ryoko's past to her... and Ryoko even got to meet her grandfather, the ruler of the Balta Guild. But even though she was invited to come back home, Ryoko chose to stay with Seina.
Ryoko then became a member of the newest ship in the Galaxy Police's fleet - the Kamidake II, which was created by Washu Hakubi. Mostly out of love for the boy, Ryoko, along with Amane, Kiriko - and later the child-like former priestess Neju Na Melmas - fought alongside Seina, which included rescuing Seina and Fuku when a rogue faction of the Galaxy Army - who were aiding Shank - tried to gain the secrets to Fuku's power.
Later on, Ryoko, as well as Amane, Kiriko and Neju, were placed in an arranged political marriage with Seina, although they all assured him that this was with their full consent. However, before the ceremony could begin, Seto's ladies-in-waiting, who were actually agents of the Renza Federation seeking to use Seina's abilities to rid their home from marauding pirates, kidnapped Seina into their small ship, and began to molest him in a public broadcast to ensure their non-Galactic Union organization's survival. As a result, the four are apparently included into the marriage, or at least the crew of the Kamidake II.