In order to stop sudden climate change, Ken used Chemical Z, a new form of the Professor's original substance Chemical X, to destroy a giant glacier. However, the impact of Chemical Z caused several black and white lights to appear in the Tokyo sky. Three ordinary girls, Momoko, Miyako, and Kaoru, were engulfed in white lights and soon became the new defenders of Tokyo City: The Powerpuff Girls Z. However, the numerous black lights caused others to turn to the side of evil. And so, using their ultra super powers, Hyper Blossom (Momoko), Rolling Bubbles (Miyako), and Powered Buttercup (Kaoru) dedicated their lives to defending Tokyo City from the likes of those swayed by the black lights and Him's black powder.
The Powerpuff Girls Z are the main heroines of the series. They are three thirteen-year-old girls from three different families, unlike the original Powerpuff Girls who were sisters created by Professor Utonium and attended kindergarten. When Chemical Z exploded into multiple black and white lights, Momoko Akatsutsumi, Miyako Gotokuji, and Kaoru Matsubara received white lights when they protected nearby children from it. Under the condition to keep their identity a secret as long as their needs were met, the girls transform into Hyper Blossom, Rolling Bubbles, and Powered Buttercup to protect Tokyo City. Momoko, Miyako and Kaoru use a yo-yo, a bubble wand and a hammer as their weapons, respectively. In addition, they all have basic abilities such as enhanced strength, enhanced speed, flight, weapon materialization, and atmosphere resistance. Their costumes also have some special abilities, including the ability to fit anyone of any size and withstand strong physical impact. The girls' battle cry is "The Lovely Fighting Science Legend: Powerpuff Girls Z!"
* Momoko Akatsutsumi (赤堤ももこ, Akatsutsumi Momoko)/ Hyper Blossom (ハイパー・ブロッサム, Haipā Burossamu, Seiyū: Emiri Katou). Momoko is the first member of the Powerpuff Girls Z squad and the main character of the series. She spends a great deal of her time eating candy and dreaming about boys. She's also a bit of whiner and can act a bit spoiled. But as the leader of the powerpuff girls z, she's usually the first to come up with plans against the bad guys. She transforms using the phrase "Hyper Blossom" and uses a yo-yo. Like the original, she's the self-proclaimed leader of the team. However, she is more or less unlike her original counterpart as she is not as intelligent, is a bit boy-crazy by giving to crushes and romantic fantasies, and is an otaku. She is very familiar with the mahou shōjo genre, along with some typical anime/super sentai concepts and is regarded as a "hero maniac" in school, especially by Kaoru. Momoko also has a strong appetite for candy and other sweets and spends much of her time snacking. Because of this, most of her attacks are named after types of food, most often sweets. Additionally, she dislikes celery and is afraid of bugs and dentists. Although often distracted and has been known to whine, Momoko tries her best to protect Tokyo City, lead the girls, and help her friends regardless of her situation (In one instance, when Momoko is unable to transform, she tries to fight alongside Bubbles and Buttercup wearing a sentai hero mask). Often she can be very clever and crafty when needed, usually being the first to come up with a plan to trick or defeat a monster that the girls are having trouble with. She has a younger sister named Kuriko. She is represented by hearts. She dreams of being married in the future.
* Miyako Gotokuji (豪徳寺みやこ, Gōtokuji Miyako)/Rolling Bubbles (ローリング・バブルス, Rōringu Baburusu, Seiyū: Nami Miyahara). Miyako is the second member of the Powerpuff Girls Z team. She transforms using the phrase "Rolling Bubbles" and uses a bubble wand as a weapon. She is quite friendly and trendy, so it's no surprise that she's popular among boys. She can also a bit clueless. However, she is respectful of others,and can be quite mature. In comparison to the original Bubbles, who was known for being the most childish of the girls, Miyako is the ditsiest member of the three, often appearing a bit clueless, and doesn't seem to understand her powers completely, along with a few other things. She is the only member of the girls who, like some villains, end a few sentences with a phrase; hers is desu wa. She is, however, a little more mature than some of the girls in the team and will try to calm any situation, although she too can be angered when provoked. She is also very polite and always uses honorifics at the end of names. She is more concerned with shopping, her appearance and her outfits, and perhaps because of this, she seems to be very popular among her male classmates. While she seems oblivious to the many boys that love her, she already "loves" Takaaki (or Taka-chan as she called him), a boy on whom she maybe has had a crush ever since she was six years old. She retains her hairstyle during the reimagining, but her pigtails are slightly longer, and curl into ringlets. She also uses curlers (3 balls on each pigtail) when going to bed. Miyako/Bubbles remains typified, however, by the original's compassion, gentleness and innocence, as well as her love of animals and her favorite doll, Octi. In episode 34, it is revealed she lives with only her grandmother. Her parents live in Kyoto. The reason for this is yet left unexplained. She is represented by bubbles. She dreams of being a fashion designer or model in the future.
* Kaoru Matsubara (松原かおる, Matsubara Kaor)/Powered Buttercup (パワード・バターカップ, Pawādo Batākapp, Seiyū: Machiko Kawana). Kaoru is the third and final member of the Powerpuff Girls Z team. She transforms using the phrase "Powered Buttercup" and uses a Daruma Otoshi hammer. She hates skirts and other girly things-in fact, she even hates girls. Like the original Buttercup, Kaoru is a tomboy and is the most easily enraged of the three. She is known at school for being the most athletic girl as she plays tennis, practices martial arts, and numerous other activities, and spends a great deal of time watching sports on television. She is especially good at soccer due to her strengthened determination after receiving new soccer cleats from her brothers when she was younger. This may be part of the reason why she has so many fangirls, much to her dismay. She dislikes girls, who she considers very "girly". This includes Momoko and Miyako. This, in addition to the fact that she hates skirts, makes Kaoru the most reluctant of the girls, only joining due to the power it has given her. In later episodes, she begins to care about Momoko and Miyako and is no longer reluctant about joining them in whatever they do, but she often tries to act calm and indifferent. She speaks with a hard and masculine edge and rarely uses honorifics when speaking. Her greatest fear is ghosts. Kaoru lives with her father, who is a professional masked-wrestler, mother and two brothers, one older and one younger. It is thought that she has feelings for Butch because in episode 51 when the girls kissed the rowdyruff boys, Buttercup was the last to stop because she was told that she could stop now. She is represented by stars. She dreams of being a professional wrestler like her dad in the future.
* Professor Utonium (ユートニウム博士, Yūtoniumu-Hakase, Seiyū: Taiten Kusunoki): This series' version of Professor Utonium. His real name is unknown, aside from his family name Kitazawa (北沢). In this incarnation, he has a son named Ken, who is responsible for all those affected by the Chemical Z lights, especially the Powerpuff Girls Z. Professor Utonium was originally experimenting with the substance Chemical X and strove to find a way to change its chemical properties. Professor Utonium has created several inventions throughout the series; the most important one being his Chemical Z Particle Ray, which allows him to transform those affected by the lights back to normal (although it doesn't prevent recurring transformations nor is it able to work on all black light victims). He seems to be aware of the effect Ken's lack of a mother has had on his son, assuming that it had caused him to be a bully to the girls. However, this does not change his behavior towards Ken. He appears to be a gentle father figure like the original Professor Utonium was in The Powerpuff Girls. He treats the girls like members of his family and is very close to the Mayor and Miss Bellum. While he is very gentle and serious, Professor Utonium may, at times, act a little less mature than he usually does.
In episode 37, when the Powerpuff Girls Z are "grounded" from using their powers for a day when they have to take a test in school, Professor Utonium fills in for them, donning an exosuit with a laser beam gun and rocket pack, calling himself "Utonium Z" (this is most likely based on the American cartoon episode "Powerprof" in which he also donned a fighting suit but drove the girls crazy with lame one-liners during battles). He also appears to have a mecha that looks like Utonium Z, which he uses against the Mojo Robo. Although he seems unsuccessful at first, he is able to defeat Mojo Jojo, Fuzzy Lumpkins, and the Amoeba Boys. His main attack is the Uto Beam. At the end of the episode, Ken, Peach and himself call themselves "Powerpuff Boys Z" as their own self-proclaimed superhero team.
* Ken Kitazawa (北沢ケン, Kitazawa Ken, Seiyū: Makiko Ohmoto): A young boy genius, the 8 year-old son of Professor Utonium who is somewhat responsible for turning regular girls into the Powerpuff Girls Z and numerous other characters into villains using Chemical Z. He used it to blast a glacier in order to set the weather back to normal, but the impact resulted in the explosion of several lights, which affected all those who came in contact with it. Despite being younger than the girls, he acts a lot more mature and the education he receives from his father is considered more advanced than what the girls learn in their school, earning his PhD at an early age. Ken, in a later episode, attended school in order to gain social skills and make friends. While he considers grade school life boring, he has made several friends, including Jou (who was originally his rival) and Kuriko (Momoko's little sister). Ken sees the girls as older sisters and has to often put up with them, though he still cares for them deeply. Ken interchanges between calling Professor Utonium Papa and Professor. During a serious situation (such as a monster attack or investigative purposes) he will try to refer to Utonium as "Professor," but in less serious situations (like packing a lunch) he will call him "Papa." Ken often corrects himself, because he usually uses the wrong honorific (eg. "Papa, I mean, Professor").
In Episode 26, it is revealed that Ken's mother works on a space station, therefore making her very busy and unable to be with Ken. Thanks to the girls and Santa Claus (whom he believed did not exist at first based on a 70% possibility), he was able to see her and is now able to communicate with her clearly on the lab's monitor. In episode 37, when the Powerpuff Girls Z are "grounded" from using their powers for a day when they have to take a test in school, Ken fills in for them, donning a superhero suit consisting of a black bodysuit, a white cape, white gloves, white boots, a red vest with gold shoulder pads and a yellow "Z" on it, and a blue helmet with the yellow letters "KK" on it, while brandishing a blue polearm with a yellow "U" at the end, and calling himself "Ken Kitazawa Z". Despite having no powers or attacks, he uses traps and other props as weapons when he defends their lab from the Gangreen Gang, ultimately driving them off by tricking them into drinking bottles of hot sauce (thinking they were the containers of Chemical Z). Ken's pre-production art bares a strong resemblance to Dexter from Dexter's Laboratory, even the current incarnation. However, in one of the special edition DVD booklets, it is explained the design originated from Kid Utonium from the original series.
* Peach (ピーチ, Pīchi, Seiyū: Tomoko Kaneda): Ken's pet robot dog. Peach was also affected by a white light, gaining the ability to talk, as well as a considerable boost in intelligence. Peach's shout prompts the girls to transform either in person or through a long-distance communication device, although a modification to the girls' compacts allows them to transform on their own. Additionally, Peach can re-summon the girls' powers, even when their powers are drained. Peach is also capable of sniffing out those who are affected by the black lights, white lights, and Him's black particles. The black light monsters/villains that have been sniffed by Peach are stored in his data banks for later reference. This ability, however, is hindered if his target is wearing heavy cosmetics (as was the case with Sedusa). Peach is also capable of sniffing and identifying others more clearly than other dogs, even when someone's appearance has been completely changed. Peach's phrases always end with a bark (or "wan," literally his bark). He is also able to understand cats. It is possible Peach is based after "The Talking Dog" as well as the Powerpuff Hotline. Like many recurring characters, he was given his own symbol, a Bone.
In episode 37, when the Powerpuff Girls Z are "grounded" from using their powers for a day when they have to take a test in school, Peach fills in for them, wearing a skintight brown jumpsuit with black trim, and brandishing a nunchaku made of two bones linked together, and calling himself "Peach Z". He assists Ken in dealing with the Gangreen Gang, making short work of them with his nunchaku.
* Mayor Mayer (メイヤー市長, Meiyā Shichō, Seiyū: Hideyuki Tanaka): The Mayor of Tokyo City. His design is distinctly different from his American counterpart, as he is of normal height and has no monocle or top hat. A caveman version of the Mayor that is closer to the original design does make an appearance in episode 51 briefly. While less extreme in comparison to the Mayor of Townsville, the Mayor of Tokyo is very childish and has a very short attention span. He seems to worry quite a lot when the girls are fighting, and wishes that they could cause a little less damage. The Mayor, like many of the characters in the anime, loves sweets. The Mayor also has a younger brother, who is the Principal of the school Momoko, Miyako, and Kaoru attend. It was through him that Miss Bellum and the Mayor were able rearrange the classes, so that the girls would be in the same class. However, the Mayor and the Principal, don't always get along, and even the most minor of things will set off an argument, which often time leads to name calling. He also deals with his brother when the girls aren't doing well in class due to them skipping class to save the city.
* Miss Bellum (ミス・ベラム, Misu Beramu, Seiyū: Yōko Kawanami English Voice Actor: Nicole Oliver): Like the original Miss Bellum, her face doesn't appear on screen; however, unlike the original, she is now blonde. Usually, Miss Bellum covers her face with a tablet computer, which has lips imprinted on it. While the Mayor is different from his original counterpart, Miss Bellum still does most of his work for him, and still appears to be the brains of the operation. She also instructs the girls a bit, which she has done several times in the original. Fuzzy Lumpkins has a crush on her; however, she dislikes Fuzzy.
In Episode 51, a pre-historic version of Miss Bellum is shown as the inventor of fire after being hit by a way-ward Chemical Z Light particle that scattered across Earth's timeline. At one point in pre-production, Miss Bellum had facial features.
* Miss Keane (キーン先生, Kīn-sensei, Seiyū: Tomoko Akiya): Another "returning" supporting character, Ms. Keane first appears in episode 3. She is very pretty and loved by her male students, although the female students don't like her as much, especially Himeko. Miss Keane, like the original, is kind and incredibly patient. She is talented in many ways, which she used to counter Momoko, Miyako, and Kaoru's excuses; this includes knowledge on medicine for non-existent medical conditions, such as dislocation of the stomach, and is able to speak mole and English. She is also unfazed by the destruction Mojo causes and speaks to him as if he were a normal human being. In fact, in episode 33 when Mojo asks her out on a date, she gladly accepts and even enjoys the date (though she still treats him as a monkey, as in ordering a "monkey ticket" for him at a movie house while getting an adult ticket for herself). At the end of that episode, though, it is also revealed that Miss Keane has a mole-man boyfriend named Uneo, who appears in an earth-tunneling vehicle that emerges from the ground to pick her up.