Her father, Masanori Yukine, was a violinist. Her mother, Sonnet M. Yukine, was a vocalist. Both parents were famous musicians being looked into by the Second Division in order to look for candidates for the Symphogear.
Eight years prior to S1, as part of a non-government volunteer organization, Chris' parents took a young Chris with them to a republic that recently suffered from a coup and had suspended all diplomatic relations with other countries: the Val Verde Commonwealth. They entered the country through Guatemala and put on public music performances in different places while traveling, with the ultimate goal of lending aid to refugees. At first, they traveled along with delegates from the United Nations, but they eventually got trapped by the expanding front-lines of the ongoing war and became isolated from their organization. They were later declared missing. Shortly after that, outside sources confirmed that Masanori and Sonnet had died in a terrorist attack, but they were continually unable to determine what exactly had become of Chris.
It turned out that Chris had been kidnapped by the terrorists and sold into sex trafficking. Two years prior to S1, Chris was rescued from the clutches of a local gang by the United Nations during their intervention in Val Verde. She was then returned to Japan. Genjūrō Kazanari was arranged to be her legal guardian after he volunteered to take her in, but upon her arrival in Japan, Chris was instead kidnapped by Finé to be used as a tool in Finé's plans and experiments. Though many agents, Genjūrō included, were sent to find her, Finé foiled all their efforts and made several die or even disappear. Thus, the search for Chris was called off.
Chris has since been living in isolation with Finé in Finé's mansion in the remote country. Sometime during the two year gap between the concert tragedy and Hibiki Tachibana's awakening of Gungnir, Finé gave Ichaival to Chris and, after obtaining Solomon's Cane from the American government, proceeded to exploit her song to awaken Solomon's Cane and allow Finé full control over the Noise. The awakening of Solomon's Cane took half a year to complete, according to Chris. Since then, Chris has refused to use Ichaival, out of her guilt over awakening a weapon of destruction, and her hatred of songs caused by her refusal to accept the deaths of her musician parents.
As a villain
Chris mocks Tsubasa as she reveals Solomon's Cane. They both yell at Hibiki as she tries to stop the fighting. Chris attacks first and blocks Tsubasa's own attack with the use of the chains. She effortlessly fights and blocks all of Tsubasa's attacks and kicks her back. Using the chain as a whip she tries to attack Tsubasa and summons Noise to keep Hibiki out of her way. Tsubasa continues to attack her as she blocks and throws her back down. She reveals that the plan was to abduct Hibiki the entire time.
As she talks Tsubasa uses her One Thousand Tears to force her to move and allow Tsubasa the space to get away. The two continue to fight as Chris summons more Noise. After Tsubasa destroys them all Chris uses her Nirvana Gedon which causes an explosion as Tsubasa tries to block. She tries to fight as Tsubasa gets up but finds that she cannot move due to Tsubasa's Shadow Weaving. As Tsubasa sings her Zesshou Chris tries to summon a group a Noise to stop her only to see that Tsubasa has already reached her.
As Tsubasa finishes Chris is thrown back as the Nehushtan Armor is damaged. As it starts to repair Chris leaves the battle scene.
Later on, Chris is seen to be working with Finé and is punished with electrocution for her failure in capturing Hibiki. Later she is present at the attack on Hibiki and Ryoko during their transportation of Durandal. She is shocked by the fact that Hibiki was now able to fight the Noise as before she could barely use her Symphogear. She then steps in and kicks Hibiki before attempting to grab Durandal in which Hibiki knocks her out of the way. Out of anger Chris summons Noise before being blown away.
Later Chris is seen thinking about her past and childhood while feeling bitter toward Hibiki. As Finé appears Chris throws Solomon's Cane at Finé proclaiming that she can do what Finé wants without it. Later on Chris finds Hibiki and attacks her, but also attacking Miku in the process. She follows Hibiki away from Miku and attacks her. She expresses confusion at Hibiki's attampt at to talk to her and continues attacking. She is punches by Hibiki and the Nehustan Armour starts to crack.
Hibiki's words anger Chris and causes her to retaliate and harshly fight Hibiki. As the Nehustan Armor slowly regenerates Chris uses her Armour Purge and transform for the first time with the use of the Relic Ichaival. She proceeds to relentlessly attack Hibiki with the use of her newly revealed Relic. As the smoke clears she finds that Tsubsa had protected Hibiki from the attacks. She and Tsubasa begin to fight and Chris is unable to land any damage and prepares to continue fighting before Noise come down and damage her Armed Gear and attempt to harm her. She is saved by Hibiki and catches her afterwards.
Redemption and road to heroism
As Finé appears and discards Chris, Chris chases after her. Later in the night Chris walks alone and thinks about the fight from earlier. She finds children in the park and offers to help the children find their father. In the end she goes off the Finé's hideout and confronts her about being thrown away and is cornered by the Noise and Finé.
Having transformed Chris is running from a small group of Noise, she collaspes in a back alley after destroying all the Noise. She wakes up as Miku is caring for her and find that she was wearing Miku's clothes. She pulls the comforter around herself in embarassment as she isn't wearing underwear as Miku didn't give her any. She later thanks Miku for her care and comments that Miku is quiet. She tells Miku that she had been alone ever since her parents died and even then that they were half way around the world, and since then had never had friends.
She expresses her bitterness toward Finé for using her, having thought that Finé was the only one who had understood her. Chris also tells Miku to beat the shit out of whoever she had fought with and then make up. Confused at Miku's thanks Chris also gives Miku her name and is told that she wasn't a bad person. She pulls away at Miku's offer of friendship and admits to having done terrible things to her as the Noise Alarm goes off.
She is found by Noise after running off and tries to transform unsucessfully before being saved by Genjuro. Afterwards she transforms and fights off the Noise.
Chris is found by Genjuro who brings her food in which she was supicious of. After Genjuro finishes speaking and she finishes eating Chris jumps out a window before transforming and running away. Later on Chris tries to fight off a large group of Noise before Hibiki comes to her aid. After the battle Chris knocks over trashcans and wonders why she helped Hibiki as she was the enemy.
- According to notes from the manga:
- Chris is half-Japanese, half-American. She was born in Japan.
- Her strange way of speaking comes from her time spent overseas, and being home-schooled by her parents. It can be inferred from this that she never went to public school before season 2 of the anime.
- Her favourite food is anpan (bread filled with red bean paste).
- When she was living with Finé, Finé would "help" Chris with the shoulder and neck pains caused by her large breasts by electrocuting her with a low-power current on the parrilla.
- Chris' battle song genre is rock.
- Almost all of Chris's various attacks are references to the Mobile Suit Gundam franchise, most obvious in Billion Maiden utilizing the same weapons and firing pose as Heavy arms Custom but also in her superb song, which chains together the ultimate attacks of the Turn A, Double X and Wing Zero.
- Chris is the first person to have used two relics, the second being Maria Cadenzavna Eve.
- She is the first user to hold a full relic, the other being Finé.
- Chris is the only user to use a Spanish word in her song; she says "adios", which means goodbye.
- Interestingly, she lived in South America for six years. It's possible she picked up some Spanish from the time she was in trafficking there.
- Finé gave Chris all the clothing she wore as a teenager in season 1.
- In episode 8 of season 1, Chris appears to have on her back what looks like burn marks, most likely from being electrocuted on the parrilla given their patterned spread.
- In episode 1 of season 1, on the day of the concert tragedy, Miku's father can be seen reading a newspaper that mentions a Japanese girl missing and the South American civil war, referring to Chris. It can be inferred from this that Finé kidnapped Chris recently to the concert event, possibly a few weeks or even days before.
- Despite Chris having hair bows/ribbons in most concept art for season 1, and having hair scrunchies in the manga version, she has no such hair accessories as a teenager in season 1 itself; only her child self has hair accessories. Season 2 and onwards depicts her with the hair scrunchies from the manga, although they are rose-pink in colour compared to the manga's dark-red.
- Chris' short stature is likely in part because of her time in sex trafficking, where she would have undergone a lot of stress and been underfed as incentive to keep her in line, thus leading to her growing up somewhat stunted. This can also explain why she has such a big appetite and is such a messy eater, from having to cherish every scrap of food she managed to get her hands on, and the harsh nature of trafficking discouraging polite social etiquette.
- GX shows Chris to be able to get good grades at school. This seems strange at first, as she lacked eight years of formal education due to trafficking and living with Finé (though some fans speculate Finé homeschooled her to an extent, logically it wouldn't be enough to make up for the six years Chris missed with trafficking). It makes sense when one considers Chris' fighting style: using guns and bows requires her to calculate range and wind direction and the best tactics to avoid mishaps and hitting her friends. This would give Chris a natural advantage in things like mathematics which she can apply to and from school and battle. Furthermore, Chris has also shown herself to be clever and creative when it comes to making up plans and gambits on the spot, such as in S1E10 where she suggests the plan to take out the Noise ships, and in later episodes of S2 where she subtly lets Tsubasa in on her plans to take out Ver and retrieve Solomon's Cane without alerting him to her betrayal.
- One of the main weapons of Ichaival is guns, which is a weapon constantly used in warfare, terrorism, and also sometimes in trafficking and slavery to keep slaves in line. It's possible that one reason Chris refused to use Ichaival is because of the role of guns in her time in South America.