Chieri Sono is the main protagonist in the AKB0048 anime series, alongside Nagisa Motomiya. She is also known as Cherry by her fans as a member of AKB0048. She is the heiress of the Zodiac Corporation and one of the AKB0048's trainees. She currently holds the Center Nova position.
The official AKB0048's website describes her "She has a cool personality and her seriousness and dedication surpasses that of the other girls. She is also the daughter of a large conglomerate." She speaks her mind regardless of what anyone else will think, to the point of being considered rude by some of her peers, though she does it to help her friends and team mates. In the second season her personality has changed considerably, being more ongoing and cheerful.
4 years ago, whilst visting Lancastar, Chieri brought Nagisa, Yuka and Orine to an abandoned mine where an AKB0048 concert was held. After witnessing the concert and the battle between AKB0048 and the DES soldiers, in which AKB0048 won the battle, the four girls vowed to join one day AKB0048. After the concert, a Kirara followed her home. The Kirara has been with her ever since.
In present time, Chieri is first shown at the space airport where she bumps past Yuka and Orine by mistake, closely followed by her pet Kirara close by. She is later featured on a news channel, where it is announced that she has gone mysteriously missing. Chieri is in fact on the ship, in disguise to hide her identity. Chieri later confronts Nagisa during the DES attack on the ship they are travelling on, telling her that she must view everyone as a rival. The chandelier then comes crashing down on top of Nagisa, but Chieri saves her by pushing her, which results Chieri to be trapped under the chandelier, but, thanks to the efforts of Nagisa and Yuuko that she is saved.
During the qualifying round, Chieri continues to isolate herself from the other girls, including Nagisa. Her cold attitude does not endear her to the others, especially Yuka who gets angry with Chieri despite admitting the latter's serious approach regarding AKB0048 is not wrong. During the test on the guerilla concert, Chieri takes a bullet to protect Nagisa, only to find that it was a paintball and she passed the test. At this point, the girls warm up to her.
Upon arrival at Akibastar, Chieri seems the least impressed upon meeting Mimori and Kanata. When Ushiyama asks Chieri to take center stage during dance practice, Chieri refuses, stating that she wants to see her superiors perform and how it is done, causing Kanata to run off crying and Sonata to berate Chieri for treating her sister so poorly. As the other girls go after Kanata, Nagisa confronts Chieri about her attitude, and Chieri responds that while she is impressed with Kanata's skills, she doesn't see a point in Kanata being there if she doesn't want to be. While the other six members of the 77th Generation find Kanata and Mimori and sing with them, Chieri is shown getting on a train into the city by herself.
During Episode 5, on their day off, Chieri sets off into the city alone to do some shopping, with Nagisa tagging behind. Nagisa eventually catches up to her, and after a brief misunderstanding with a man, the two talk a bit by the river, to have Yuuko startle them by taking a candid shot of the two girls. Yuuko then takes Chieri and Nagisa and shows them previous photos of AKB0048's members, including previous Center Position, Atsuko Maeda. Yuuko then runs off, and both Chieri and Nagisa express their admiration for her. The two vow to practice their dancing until they are good as Yuuko. They begin to imitate Yuuko's dancing and quickly attracted people's attention which they gave Chieri and Nagisa an applause for their skill.
In Episode 6, Orine receives a letter from a hater, resulting in her performing badly during dance practice. Chieri berates her for it and she runs away crying. Afterwards, Nagisa confronts Chieri about the incident but she tells her that if Orine can’t overcome this hurdle they won’t be able to achieve the dream of becoming successors together. Some time later, the girls participate in their first handshake event and when Orine’s hater appears, Chieri confronts him and protects Orine.
In Episode 7, some of the members are leaving for a peace conference and need to be replaced during their absence, so Tsubasa decides to reestablish the stand-in system. Chieri is picked as a stand-in for Yuuko, causing Nagisa, who is a fan of Yuuko, to get slightly jealous. After seeing how hard Chieri’s working in her practices, however, Nagisa gets over her jealousy and decides to support Chieri. Unfortunately, some understudies from the 76th Generation find out that Chieri is the heir of Zodiac and accuse her of being a spy. Chieri is about to quit the group as she feels she doesn’t deserve to be there, but Kanata stops her, telling her that her dream of being an idol has nothing to do with her father’s company, and that she isn’t alone as all her friends and teammates are there for her.
During the AKB trial in Episode 14, she speaks up to the court and delivers a pasionate speech, which makes her popularity increase. When she finds out that her father had been involved in the trial, and had sponsored a CM for her, she begins to resent her popularity. She tells Tsubasa that if she gets elected, she will graduate (quit) from the group.
At the General Elections, she gets elected, ranking 6th (9th in early results), but decides not to graduate as she realizes it would be disrespecful to her fans. After the General Elections, she and Nagisa declare their rivalry and their Kirara glow brightly together. Ooshima Yuuko said that light is just like Atsuko Maeda the 13th.
Due to becoming an elected member, her popularity increases even more and she does many concerts with the other elected members. Rumors also begin to circulate that she might succeed Atsuko Maeda.
In Episode 19, Chieri notices Nagisa is acting strange, but after Nagisa overcomes her doubts, Chieri notes that she is beginning to change. During the elected members' concert, Chieri and Yuuko both shine brightly performing Ponytail to Shushu. Chieri tells Yuuko that she will beat her but Yuuko replies that Chieri's radiance is not at Acchan's level yet.
In Episode 24, Chieri and Nagisa travel to Sagittariusstar to meet with Chieri's father. While they wait in her family mansion, Chieri tells Nagisa that she was always by herself during her childhood. Her father was hardly ever home, so she only had her servants, tutors, and self-defense instructor to keep her company. She also states that Nagisa, Yuka, and Orine were her first friends, and that her mother and brother had died. Later on, they meet with Chieri's father and Chieri tells him that she’ll become a Center Nova for him if he spare Nagisa and the group. He accepts and she shows him her radiance through an acappella performance of Hoshi no Mukougawa. As she finishes her song, her father is shot. Soon after, she and Nagisa are sent back to the Flying Get by Yasunaga.
In Episode 26, the last episode of the series, Chieri becomes the new Center Nova.