Very little is known about Juri's past prior to the First Alliance-PLANT War. Sometime in mid C.E. 71, Juri was asked by Morgenroete head Erica Simmons to board the Junk Guild's ship H.O.M.E., take control of the MBF-P02 Gundam Astray Red Frame and figure out how it can allow a Natural to pilot it. Joining the Guild under the alias "Marlin", she is able to get close to the team there and take control of the Red Frame. When its pilot, Junk Guild tech Lowe Guele races after them, he catches up just in time as a ZAFT mercenary arrives in an attempt to destroy the Red Frame itself. Lowe is able to retake control of the Red Frame and, thanks to Juri's unfamiliarity of the Red Frame's Gerbera Straight katana, is able to give the Red Frame a new attack. Soon after, "Marlin" is dismissed from the Junk Guild, but her mission was complete anyway.
When Lowe and his team arrived in Orb, Juri reunites with him and introduces him to her fellow test pilots Asagi Caldwell and Mayura Labatt, where Juri claims Lowe "hers", causing plenty of confusion for Lowe and plenty of jealousy for Lowe's friend Kisato Yamabuki. However, after noticing Kisato's care and worry for Lowe after his test match with Rondo Gina Sahaku, she opted to back off.
The Invasion of Orb and The End
Weeks later, Orb would find itself invaded by the Earth Alliance, now lead by de facto leader Muruta Azrael. Juri would take up her M1 Astray and join the rest of the Astray army, as well as those on board the battleship Archangel in defense of Orb. Though the first invasion is stopped, Juri is forced to join the others in escaping Orb and into outer space.