A young man living on the GUARDIANS Colony. While attending a celebration commemorating the centennial of the Tripartite Treaty, he and his sister Lumia are caught in a SEED attack. After this experience, Ethan joins the interplanetary security force, the GUARDIANS, and begins training under Karen Erra.

After three years of experience with the GUARDIANS, Karen was assigned as Ethan's instructor. As a girl, her mother was killed by native creatures, and although she is a newman, she is unable to use TECHNICs for some reason. To compensate for this deficiency, Karen pushes herself to do her best, sometimes overly hard.

A Guardian who attended the GUARDIANS Training School at the same time as Ethan. He and Ethan are rivals, often competing for first place in the Colony Frabullu Tournament. He's a bit of a lothario, but also a devout follower of the Gurhal Faith, and claims that all the girls he has met have come to him through divine intervention. At heart he is a very diligent prodigy.

Goes by "Leo." He encountered Ethan during the initial SEED invasion, and after fighting alongside him recommended that Ethan join the GUARDIANS. Since then, they've formed a brotherly bond. Despite his rough facade, Leo has a big heart and cares a great deal about his family and friends. He has a wife and a three-year-old son on the GUARDIANS Colony.

To a human, he appears to be a young boy, but he's a fully-grown small beast. Tonnio was raised in an orphanage and formerly led a street gang. After meeting Leo, he turned his life around and joined the GUARDIANS. Still, he has a rough, easily angered, and sometimes uncontrollable personality.

A member of the GUARDIANS Investigation Section. Because she specializes in intelligence-related missions, Lou has special equipment that other Guardians do not. For the sake of her special missions, she has been programmed not to exhibit excess emotion. When necessary, she shares pertinent information, but there is something about her that Ethan can't quite put his finger on.

A researcher with the GUARDIANS Research and Development Department that develops equipment used by the GUARDIANS. She and Karen have a sisterly relationship. Her sultry appearance can be misleading, as her personality is a little on the goofy side. She is partial to goods made with photons.

A Guardian since the organization was first established, he's the oldest member of the GUARDIANS and headmaster of the GUARDIANS Training School. Many Guardians trained directly under him, including the current president, and he has a faithful memory of each student, particularly their weak spots. He is held in great esteem. His strength is still plentiful, although his body has succumbed to a common CAST ailment.

The GUARDIANS' seventeenth president. He has great expectations of himself, as well as of his subordinates. At a glance, he appears to be quiet and reserved, but those who know him well say he is talkative and tells many jokes.

Official name is "GHX-005." Ethan's partner machine, received when he graduated from GUARDIANS Training School. Manages Ethan's schedule and gathers information about Ethan's missions. A reliable companion.

Ethan's younger sister. She is observant and kind to everybody. Lumia is a big fan of the Communion of Gurhal's Divine Maiden and participates in many ceremonies just to get a glimpse of her. She's just as full of vigor as her brother, sometimes taking the reins and leading him around. She is concerned that Ethan has chosen the same dangerous line of work that killed their father, but supports him nonetheless.

Said to be one of the researchers who discovered A-Photons. He is currently affiliated with the GUARDIANS, searching for a trump card to use against the SEED.

A captain and platoon leader of the Counter-SEED 177th Unit. Knowing nothing of life outside the military, he obeys orders from his superiors without question. A lifetime supporter of CAST supremacy, he believes that CASTs are superior to the other races. After many missions spent dealing with disputes, he has grown to be distrustful of non-CASTs.

The commanding officer of the RELICS Control Division of the Endrum Collective, a section of the Alliance Military charged with the investigation and protection of RELICS. He is not formally a military officer, so he has no official rank. Above all, he loves to fight, and as a mercenary soldier looking for a battle, he executes his missions for the Endrum Collective faithfully.

An assistant professor in the engineering department of Parum's Rozenom City University. Kou originally specialized in photons, but switched his specialty to A-Photons. Maya Shidow was a student of his during his photon days.

An archaeology professor who enlists the help of the GUARDIANS to investigate a RELICS site. The study of RELICS is his life. It appears that he has some sort of connection to the Endrum Collective...

A popular reporter on Gurhal's Channel 5. She is something of a chameleon; she can take on a serious tone at one moment, then become tongue-in-cheek the next. This unpredictable personality gimmick seems to attract enough people that she's become a popular icon with the citizens. Still, rumor has it that she may be a virtual idol, particularly because of her personality switches.

Kalam, the sole heir to a the famous Green Green Farm koltova ranch in Raffon Meadow, and the farm's assistant, a female CAST named Norphe. Norphe has taken over raising Kalam, who has been very closed off ever since his parents passed away. Unable to understand his human emotions, she is having a difficult time communicating with him.

The Divine Maiden, symbol of the Communion of Gurhal. Kind and compassionate, her grace and beauty offer spiritual support to the followers of the Gurhal Faith. She first encounters Ethan en route to the Tripartite Treaty Centennial Celebration.

A Light Master in one of the four top positions within the Communion of Gurhal. As the Light Master of Festa, he controls the overall festas and ceremonies, such as the "Rite of Divination" and "Festa of Holy Light." He is Mirei Mikuna's father.

The Chief Photon Master, and the leader of the Communion of Gurhal. His gentle demeanor quickly puts people at ease.

A powerful figure, admired by other rogues. He doesn't advocate killing needlessly, nor stealing from the poor. He believes in honor and will not betray those close to him. By his tendency to avoid bloodshed, it is clear he doesn't care for violence. However, he will not hesitate in resorting to it when necessary. He is captain of the pirate ship Landeel.

Liina was raised in the same orphanage as Tonnio and thinks of him as an older brother. As a young girl, she led an aimless existence until Tylor took her onto his staff of the Landeel as his assistant. She has a compassionate heart and dislikes taking lives. She is convinced that she is in love with Tylor.

The Vol Brothers vowed to get big in the rogue world. The eldest is the leader and the brains of the three, and uses TECHNICs. The middle brother is the brawn, and uses firearms in combat. The youngest brother is the handyman, in charge of working on machines and weapons, and is also powerful in close-quarters combat.