Suzume Kimura, better known by her nickname Zu, is one of Ruby's traveling companions and a Yellow. Her father is a delegate. For a majority of the series, she presented as selective mute; a traumatic response she experienced from the shock and fear of what happened to her when escaping Caledonia. She is a Japanese-American.
Zu was sent away to a camp Caledonia by her parents after she short-circuited her dad’s car in the middle of a freeway. Her dad is a known politician. Zu's cabin had lice and so they all had their heads shaved, she escaped the camp with Liam and Chubs who took her in
Zu is first seen in an abandoned gas station by Ruby, who pursues her to the van she, Liam, and Chubs are travelling in. Through that entire book, Zu doesn't speak at any point. According to Liam, she hasn't said a word since they broke out of the Caledonia camp. After Ruby escapes the camp with Cate and another orange, she later finds out she can't trust Cate and her boyfriend Rob. At a beaten down gas station, she escapes and finds Zu. Zu takes her into her group with Liam and Chubs. She and Ruby form a close friendship in the time they travel together. Zu gives Ruby a dress and sees Ruby like an older sister. After she, Liam Stewart, Ruby Daly and Charles "Chubs" Meriwether reach East River, she meets her cousin, Hina. After a time there, she decides to travel alongside her cousin and a few friends to reach Hina's house, where they would be safe. Liam tries to convince her to stay but fails. She asked Ruby to find her when all of that was over.
After being separated from Hina and her friends she is captured by a tracker named Gabe. He ties her up but does not seem to know what to do. Gabe eventually feels bad enough to let Zu free and he agrees to take her to find Hina and the others. When they find Zu's friends, however, they shoot Gabe, fatally wounding him, before realizing he had helped Zu.
Suzume does not make a direct appearance in this novel. According to Chubs, Zu is doing fine. He knows this because when he pretended to be a skip tracer he kept tabs on everyone.
Zu is reunited with her friends and after some time chooses to be filmed on television so people can see how children are being treated. After practicing with Vida earlier in the book, she finally decides to speak on television, leaving her friends in happiness and shock.
In The Darkest Legacy, Zu is the main character and the story is told from her point of view.
Zu, now seventeen years old, has become a spokesperson for the interim government. She believes she is fighting for the rights of Psi kids but is seen as a sellout by some of the Psi. During her speech at the re-opening of a university, Zu is baited into using her powers publicly and framed for causing an explosion that leaves seven people dead. Priyanka Acharya and Roman Volkov attempt to help Zu escape. All three are kidnapped, but are able to escape their mysterious kidnappers together.
At this point Zu has become framed for a crime and is on the run as a fugitive. The matter is made worse with politician Joseph Moore spreading rumors that she is the leader of a Psi terrorist organization called the Psion Ring. She calls Chubs, who tells Zu to find "a safe place". Zu teams up with two other teenagers, Roman and Priyanka, who travel to Haven, a place Ruby and Liam created for Psi to live in safety, only to discover that Liam and Ruby disappeared from their home two weeks prior. Following an attack on Haven, Zu sets off with Roman and Priyanka to find Ruby and uncover her role in a greater conspiracy.
She chooses to speak by writing or making gestures. Suzume appears to be very compassionate and caring when it comes to others. She is also mute for a majority of the series though this does not stop her from expressing an exuberant personality through gestures and facial expressions.
As a Yellow, Zu is able to control and manipulate any electrical current. At first she is unable to control these powers and has to use rubber gloves to avoid frying anything or anyone she touches, but she eventually gains control of her powers. During The Darkest Legacy, she becomes curious to what her limits are, and begins testing her powers during a thunderstorm, and takes control of a lightning strike, showing just how powerful of a Yellow she is.
Zu is said to be quite small, as Ruby refers to her as an eight-year-old upon meeting her, although her true age being eleven. she is Japanese. She is apparently quite adorable, which is why she was chosen as a representative to be on television. She has short cropped black hair in the book due to her cabin having had lice when she was in Caledonia, but long black hair in the movie. She is almost always seen wearing yellow rubber gloves. But in The Darkest Minds, Ruby gives her a pair of pink ones when they break into Walmart. It is stated in The Darkest Legacy that she wore pink a lot while on the run as she wanted to be seen by others how she wanted to be seen, as everything else had been taken away from her.
In The Darkest Legacy, it is said that her hair has grown long. Zu cuts her hair chin-length halfway through the book to try to find herself again after years of pretending to be someone else.
Zu met her when Ruby was trying to escape the Children's League. When Ruby was running after Zu, she went into the van and locked Ruby out. Then, seeing that Ruby was about to run from the van to make sure the Children League wouldn't find her as well, she decides to let Ruby in. Zu became very close to Ruby even though she hadn't known her for a long time. She trusted Ruby very easily and they joked around together and were very close.
Zu and Liam were in the same camp together. Zu grew close to Liam the moment that he carried her out of the camp when he planned an escape. Zu regards Liam as an older brother who tries his hardest to protect her. Protecting her could sometimes lead to him lying to her in order to maintain her innocence and not scare her.
Zu and Chubs were in the same camp together. Chubs cares a great deal for Zu, although does not believe in 'lying' to her about how things will get better as Liam does. Chubs teaches her maths when on the run to help her catch up on her missing education. After Zu declared that she would be leaving East River for her cousin Hina's beach home in California, Chubs becomes especially worried and reluctant to let her go.
When Zu and Vida first met, their relationship was a bit rocky, due to the fact that Vida thought Ruby was using Zu as an replacement for Jude, but after Vida realized that this was not the case, Vida and Zu grew to become really close in a short amount of time, Zu even deciding to practice talking with Vida before talking to anyone else.
Zu first meets Priyanka and Roman at the start of The Darkest Legacy. They are attending her speech at the university, and when the attack happens they end up getting kidnapped together. Despite not trusting her at first Zu ends up becoming quite close to Priya and at one point during The Darkest Legacy asked her if she was her friend to which Priya replies “Of course Sparky”.
Zu seemed to warm up to Roman quicker than she did to Priyanka, as she is seen letting her guard down with him multiple times throughout the book and Priyanka less. This is presumably because he was the one who came back to save her right at the start of the book, though it is never explicitly stated, and, although untrusting of his intentions at first, she eventually begins to warm up to him leading to them developing a mutual attraction to each other. They eventually kiss, and Zu becomes attached to Roman.