Jena is a pretty young girl with long silver hair kept in twin tails. Her hair is not naturally silver, but was dyed this color in order to make her look more like a blood relative of Hiljo. Her eyes, like those of Haje and Hiljo, are gray. She dresses in the same black and purple colors as Haje and Hiljo, but her clothes are form-fitted and somewhat revealing, as noted several times.
Because of her size and youth, she is one of the least physically intimidating characters and is often shown in chibi form or reacting to situations in comedic ways.
Jena has a surprisingly earnest personality. Although she has no skills and is slightly clumsy, she is courageous enough to stalk (with the intent to kill) Jin despite knowing that he is under Yi-Mae's protection. Though completely devoted to Hiljo, she also is quite headstrong and had no problem defying his orders to stay away from Jin.
However, despite her initial desire to kill Jin, Jena is revealed to be a kind, friendly girl who is trying to do what is best for her family. She is, however, easily intimidated by others and reduced to tears (usually for comedic effect) when confronted by someone who scares her, often cowering behind whomever might be nearby. Despite this, she demonstrates uncharacteristic strength and resolve through tragedy, showing that she is likely far more capable than she seems.
Yi-Mae considers her to be not all that bright since she continues to stalk Jin even after failing to assassinate him twice.
Jena has demonstrated no abilities thus far. She, presumably, has the same potential for abilities as with all other chachaoongs, but Hiljo did not foster these abilities as he raised her, hoping it would save her from being abused by Ja-Gwi. It is currently unknown what (if any) unique abilities she may possess.
- Laon Hiljo - Jena and Hiljo maintain a relationship that is similar to that of father-daughter. Hil Jo raised her from a young age and tries to protect her from Ja-Gwi but Jena is often disobedient, causing him a great deal of frustration. But in the end, her disobedience is due to her attempts to win the family's freedom by assassinating Yu Jin.
- Laon Haje - Jena and Haje are much like siblings. Though they often argued and competed for Hiljo's attention when they were very young, as they grew older, they became very close.
Jena was found by Ja-Gwi and was subsequently raised by Hiljo. Unlike most of Ja-Gwi's prisoners, Jena was marked but not maimed in any way. Hiljo convinced Ja-Gwi not to maim her and ensure dependence on him because she was female and had no fighting skills. But as a result, Jena never developed the ability to fight and is extremely clumsy.
Jena happens upon Yu Jin by accident when her curiosity leads her to go see what a school is like, as the concept is unfamiliar to her. Her first attempt to kill him results in her falling on her face, then running away, leaving him confused. Despite Hiljo's orders to stay away from him, Jena continues to stalk Jin. Her extremely clumsy attempts to attack him leaves a bewildered Yi-Mae utterly exhausted as he is not sure if he should bother killing her, or if she is just too pathetic to worry about. Yi-Mae finally captures her at Jin's request and she reveals her family's plight to the new king. Although Yi-Mae believes it pointless, he agrees to remove the trio's marks so they can be free of Ja-Gwi. However, before Yi-Mae can remove Haje and Hiljo's marks, Ja-Gwi slaughters Hiljo.
Jena is less affected by Hiljo's death than Haje. She takes him to the mountains so he can recover from the trauma. She expresses the desire to see Jin again to thank him personally for helping them, but it is unknown at this point if she will return.