Jem Ysanna was a female Human Jedi initiate. This individual, Jem, was a member of the Ysanna tribe hailing from the planet Ossus, and a descendant of the Jedi who managed to survive the destruction of Ossus caused by the Cron Supernova. Consequently, Jem possessed Force-sensitivity, utilizing her abilities as a shaman for her tribe, which was under the leadership of her father, Chief Okko. In the year 10 ABY, Jem encountered the Jedi Luke Skywalker and Kam Solusar, who had journeyed to Ossus in search of Jedi relics to aid in their struggle against the Galactic Empire. Upon sensing Skywalker's power in the Force, Jem and her sibling Rayf Ysanna requested to train with Skywalker to become Jedi Knights. Skywalker consented to instruct the pair, so he took Jem and Rayf away from Ossus aboard his vessel, the Jedi Explorer, to begin their training.
Jem, along with her brother, received tutelage in both lightsaber combat and telekinesis as she pursued her path to becoming a Jedi. During her period of instruction, Jem developed feelings for Skywalker, and they entered into a romantic relationship. As Jem and Skywalker began contemplating a shared future, their thoughts were disrupted by an assault launched by the Galactic Empire. In the midst of the conflict, Jem suffered a wound from a blaster shot fired by Tedryn-Sha, a member of Emperor Palpatine's Dark Side Elite. Despite Leia Organa Solo swiftly retaliating and avenging her, Jem's injuries proved to be fatal. The Jedi healer, Vima-Da-Boda, attempted to save her life, but Jem ultimately succumbed to her wounds after bidding a final farewell to her brother. Upon her passing, Jem became one with the Force, and her physical form vanished completely.

Jem Ysanna's birth occurred on the planet Ossus in the year 13 BBY. Jem and Rayf Ysanna, her brother, were the children of Okko, who held the position of Chief within the Ysanna tribe of Ossus. Okko was considered the most powerful Force user in the history of the Ysanna, a group that originated from the descendants of Jedi who were unable to escape the destruction of their world by the Cron Supernova. During their childhood, Jem and Rayf explored the tunnels of their planet, diligently expanding their understanding of Ossus.
In 10 ABY, Jem held the role of a shaman, and as the offspring of "The Great Okko," she and her brother Rayf were scheduled to undergo an initiation ceremony before their tribal community. As a component of the ritual of ascent, Jem and Rayf were bound to the base of an ancient tree, with the intention of imbuing them with Ysanna magic, based on the belief that the tree served as a source of power. However, prior to the completion of the ritual, it was interrupted by the Jedi Luke Skywalker and Kam Solusar. Skywalker and Solusar had arrived on Ossus aboard their ship, the Jedi Explorer, in pursuit of other Jedi. While exploring the planet in a T-77 Experimental Airspeeder, the two Jedi observed the ritual, and Skywalker detected significant Force power emanating from both Jem and Rayf. Eager to take the pair as Jedi apprentices, Skywalker activated his lightsaber with the intention of severing the ropes that bound them to the tree's base. Jem and Rayf, who only spoke the native Ysanna language and were unable to comprehend Skywalker's intentions, were terrified of the Jedi warrior, believing he intended to harm them. When Skywalker instead freed them, they fled in terror back to the Ysanna tribe members who had gathered to witness the ritual.
With the ritual disrupted, Okko commanded his people to attack the two intruders. As Jem mounted her father's riding beast, the Ysanna opened fire on Skywalker and Solusar. However, their attacks were easily deflected, forcing Okko to confront the intruders himself. Jem and her fellow Ysanna attempted to amplify Okko's untrained Force powers as he attempted to attack with The Force, but Okko was no match for Skywalker's abilities. After having his powers easily blocked, Okko came to the realization that Skywalker was a spiritual descendant of the Ysanna ancestors. The great chief embraced Skywalker and declared to the rest of the tribe that Skywalker was a Jedi, the heroes of the Ysanna legends. Unfortunately for Skywalker and the Ysanna, the celebration was swiftly interrupted by the arrival of an Imperial hunter ship, Scourge One. Through the Force, the Ysanna instinctively knew that this ship contained enemies, and as Imperial stormtroopers exited the ship, the Ysanna prepared for battle.

Under Skywalker's leadership, the Ysanna engaged the Imperials. From her position on her father's riding beast, Jem fired a concussion bow at the invaders, forcing the stormtroopers to retreat. As the Ysanna focused their fire on the Imperials, Skywalker and Solusar attacked with their lightsabers. After twenty minutes of intense fighting, the Imperial force was wiped out. However, the Imperial commanders, Executor Sedriss QL and Vill Goir exited Scourge One to continue the attack. Sedriss and Goir, both members of Emperor Palpatine's Dark Side Elite, were skilled users of the dark side of the Force and they met the Jedi in lightsaber combat. However, the Jedi proved more powerful, killing Goir and disarming Sedriss. Sedriss, the only remaining Imperial, refused to surrender and took Jem hostage. Holding her by the throat, Sedriss backed up against the very same tree that Jem had previously been tied to.
While struggling against Sedriss, Jem attempted to use the Force to repel the darksider, but Sedriss easily blocked her attacks. Realizing that Skywalker planned to train Jem as a Jedi, Sedriss claimed that he would take her back to Emperor Palpatine to turn her to the dark side. Surrounded by the Ysanna, Sedriss demanded that he be allowed to return to his ship or he would annihilate Jem using the dark side of the Force. However, unknown to Sedriss, the tree that the Ysanna had intended to use for their ritual was in fact an ancient Jedi Master. Ood Bnar, a member of the Neti species, had survived the destruction of Ossus over 4 millennia ago by transforming into his tree-like state. Bnar, awoken by the Force powers being used near his form, struck out at Sedriss, grabbing him with his roots. As the ancient Jedi prepared to sacrifice himself to destroy Sedriss, Jem tried desperately to escape. With Sedriss holding her back, Jem was in danger of being caught in Bnar's energy attack, but Skywalker risked his life to grab the young woman out of the Executor's grasp.
As Ood Bnar and Sedriss were annihilated in a beam of light, Jem and Skywalker were thrown clear of the blast, Skywalker using the Force to shield them from harm. As they fell, Jem landed on Skywalker and their eyes met. As the two stared into each other's eyes, Skywalker suddenly began to understand the Ysanna language through the power of the Force. No longer divided by the language barrier, Jem told Skywalker that she wished to be his student. The Ysanna and the Jedi then surveyed the damage, discovering that Bnar had been perched above a cache of ancient Jedi lightsabers. Bnar's death had also birthed a descendant which Jem pointed out to the group. To celebrate their victory, Rayf, Jem, Skywalker, and Solusar each pulled an ancient lightsaber from the vault Bnar had been protecting. Despite the age of the weapons, the lightsabers still worked, and the Jedi touched the tips of the ignited weapons to commemorate the moment.

Before his departure from Ossus, Skywalker made the decision to explore the planet in search of additional Jedi artifacts that could aid him in training new Jedi. Jem and Rayf assisted in this endeavor by guiding Skywalker to the Great Jedi Library. Upon entering, Skywalker and Jem examined ancient Jedi manuscripts, discovering teachings of Jedi battle meditation. As Skywalker read from the ancient tomes, Jem requested that Skywalker train her in the Force, expressing her desire to become a Jedi. Skywalker promised to train her, and the group returned to the Ysanna settlement. Although Skywalker wished to take all of the Ysanna with him for training as Jedi, Chief Okko refused. Jem's father was content to be simply Ysanna, uninterested in any further teachings. Although Okko had denied Skywalker, Jem and Rayf voiced their intent to follow the Jedi Master off Ossus and become Jedi. Okko was disturbed with his children's choice, believing that it would mean the end of the Ysanna. However, the other Ysanna chieftains accepted Jem and Rayf's choice, although they claimed that the Ysanna gods were displeased by their decision.
As the Ysanna watched them depart, Jem and Rayf boarded the Jedi Explorer, and the group departed for the Republic's Pinnacle Base. As the Jedi traveled through hyperspace, Skywalker began their training in lightsaber technique. Using a remote, Skywalker taught Jem and Rayf the basics of deflecting blaster attacks. Although Rayf was a natural with the weapon, when it was Jem's turn to face the remote, she was not as talented, and the remote stung her with its attacks. Frustrated with her ineptitude and angered by the attacks of the remote, Jem used her anger to fuel her abilities, lashing out at the training device, cutting it in two. Jem apologized to Skywalker for destroying his remote and followed him to the galley to mend the wounds that she had sustained. As Skywalker tended to her injury, Jem acknowledged a closeness with her teacher, greater than that between a master and apprentice. Skywalker acknowledged the connection, and the two kissed, beginning a romantic connection.
After arriving above Da Soocha V, the Jedi Explorer detected an approaching vessel, which was in reality a missile launched from the Galaxy Gun, a superweapon controlled by Emperor Palpatine. As Jem and Rayf observed, Skywalker and Solusar attempted to fire on the missile, but were unable to destroy it. The Jedi were left to watch as the missile collided with the world and started a chain reaction with its particle disintegrator warhead, obliterating the moon. Believing that the New Republic command was present on the moon and had been completely wiped out, Skywalker piloted his ship to the secret world of New Alderaan. As Skywalker gave the bad news of Pinnacle Moon's destruction, Jem and Rayf met two Jedi that had recently come out of hiding to help the New Republic in its fight against the Empire. Empatojayos Brand and Vima-Da-Boda greeted Jem and Rayf and began to help in their training. With Brand's help, Jem and Rayf were able to increase their telekinetic skills, lifting a heavy stone with their minds.

As their training progressed, Jem and Rayf were included in the planning of the next step against the Empire. Believing that the New Republic had been completely wiped out in the Galaxy Gun attack on the Pinnacle Moon, the group on New Alderaan decided to send out a transmission to any New Republic remnants to join them on the hidden planet. However, Skywalker's friend, Han Solo, concerned that sending a transmission from the world would signal the Empire to their location, decided to leave New Alderaan in his ship, Millennium Falcon, to send the transmission. Sending the transmission from his ship after leaving New Alderaan would keep the Empire from pinpointing the world's location. After agreeing to the plan, Jem and Skywalker made their way to a secluded area to be alone. Discussing the future, Skywalker told Jem that she was very special to him, which Jem reciprocated, kissing her Jedi teacher. However, their romantic discussion kept them unaware of a secret attack by the Empire. As Jem and Skywalker returned from their secluded spot, they failed to notice I-7 Howlrunners heading for their base.
As Jem and Skywalker returned to their separate quarters to sleep, the Dark Side Elite released Scarab Mark VI assassin droids onto the base. The droids attacked as Skywalker slept, awaking him from sleep and causing him to cry out. Alerted by Skywalker's screams, Jem and Skywalker's sister, Leia Organa Solo raced to his aid. Upon entering Skywalker's room, they encountered two of the Dark Side Elite, Tedryn-Sha and Krdys Mordi. Although Mordi scoffed at the Jedi women as inferior opponents, Jem quickly corrected him, cutting the darksider in half with her lightsaber. Now outnumbered, Tedryn-Sha was forced to back away from the attackers, pulling a blaster pistol from his holster. As Jem charged the man, Tedryn-Sha fired a shot into her belly, fatally wounding her. Organa Solo avenged Jem shortly afterwards, cutting Tedryn-Sha down with her lightsaber. With the darksiders defeated, Organa Solo cradled Jem's dying body, calling out for help. Vima-Da-Boda took Jem and laid her beside Skywalker as she attempted to heal the two through the Force. Although Vima was able to purge the poison delivered from the assassin droids from Skywalker, Jem's wounds were too great. Rayf was able to be at his sister's side at her passing, and although he pleaded with her not to die, she succumbed to her injuries and dissipated into the Force, her spirit leaving to join those of other fallen Jedi.

After becoming one with the Force, the only things that remained of Jem were her well-worn hides and Ysanna tribal clothes. Skywalker was greatly saddened by Jem's passing and attempted to apologize for her death to her brother. However, Rayf did not blame his sister's death on the Jedi Master.
Back on Ossus, Jem's father, Chief Okko was able to sense her death through the use of a Jedi meditation chamber, and he began to regret letting his children leave with the Jedi. As Rayf continued to fight alongside Skywalker and Solusar, he invoked his sister's name, especially during the attack on Vjun which defeated the Dark Side Elite, the group that was responsible for Jem's death. Rayf was later killed in the Battle of Onderon by Darth Sidious himself, after mentioning the death of his sister to the Emperor.
After the deaths of both Jem and Rayf during Skywalker's attempt to revive the Jedi Order, Skywalker was hesitant to train further Ysanna in the ways of the Force. However, the Ysanna did not hold a grudge against Skywalker and threw their full support behind Skywalker's future efforts at training Jedi. When the New Jedi Order relocated to Ossus, the Ysanna gladly welcomed the building of a Jedi Academy on Ossus.

During the time of the Galactic Civil War, Jem was an athletic woman and respected warrior within the Ysanna tribe. She had long dark hair and striking, exotic features. During her travels with Luke Skywalker, she learned how to speak Basic, but her speech often lapsed into her native language during times of stress. After meeting Skywalker, Jem aided him in his search for lost Jedi knowledge and began to feel a strong connection to him. She had short temper, not unlike her mentor, which was acknowledged during her failure in lightsaber training. Her anger caused her to lash out and destroy Skywalker's remote, concerning her master over how quickly she had turned to anger when getting frustrated.
During their travels, Jem fell in love with Skywalker, kissing him aboard the Jedi Explorer on their departure from Ossus. Skywalker returned her affection and even entertained thoughts of a future with her before her death. Skywalker was devastated upon Jem's passing, and he would not find love again until almost two years later.
As a member of the Ysanna tribe, Jem was a descendant of Jedi individuals, and she inherited Force-sensitivity from their bloodline. As noted by Luke Skywalker, Jem was strong in the Force and after minimal training, she was able to levitate large boulders alongside her brother and sense the emotions of those around her. Despite her teacher never telling her his background, Jem was able to determine things about him through the Force.
Unlike her brother, Jem was not a naturally skilled with a lightsaber, and in her first training session, she was stung several times by the training remote. This lack of skill would result in her death at the hands of Tedryn-Sha, as she was unable to dodge or block a shot from his blaster. Before her death, Jem was proficient in the use of a concussion bow and able to guide her shots through the Force. Although Jem could not initially understand Galactic Basic Standard, only fluent in the Ysanna language, she was able to pick up understanding of the foreign tongue through the Force, and was eventually able to speak it herself.
Jem Ysanna was created by Tom Veitch and illustrated by Cam Kennedy for use in the graphic novel, Star Wars: Dark Empire II. She first appeared in the third issue, World of the Ancient Sith, and was killed in the final issue, Hand of Darkness. In the audio drama version of Dark Empire II, Jem Ysanna was voiced by Glynnis Campbell. Following her death, Jem was mentioned briefly in the follow up comic series, Star Wars: Empire's End and its audio adaptation. Jem was mentioned in several reference guides relating to her appearance in Dark Empire II in the following years, but none of these guides expanded her story beyond what was seen in the original comic.
The Dark Empire II audio adaptation has some minor inconsistencies with the comic on which it was based. Most of these inconsistencies involve Jem's lines in the comic being given to other characters, and vice versa. For example, when the Jedi discover Ood Bnar's descendant, instead of Jem discovering the small Neti, it is Kam Solusar that makes the discovery. Although the comic shows Jem speaking the Ysanna language and unable to understand Skywalker initially, the audio adaptation shows her speaking Basic immediately. The adaptation omits the Ysanna language entirely, avoiding this plot point from the comic. Additionally, the audio adaptation only focuses on Jem leaving Ossus, omitting mention of her brother Rayf. As a result, Jem speaks her dying words to Leia and immediately dies after being shot by Tedryn-Sha.