The RX-8 is Mazda's proud rotary-engined successor to the third-generation RX-7. The RX-8 is notable for the fact that, despite being a full-fledged sports car with a rotary engine and FR drive, it is a family car with seating for four adults. This was at the request of Ford, Mazda's parent company at the time of its launch, as it was considered an absolutely essential condition for the development of a new rotary engine-powered car in terms of marketing strategy, as it was a four-seater that could be sold in large numbers. In order to meet the conflicting requirements of a family car while delivering full-fledged sports car performance, Mazda adopted a unique mechanism called the 'Freestyle Door', which allows the front and rear doors to open in a double-swinging motion. Within these difficult constraints, Mazda's engineering team succeeded in giving the RX-8 the very best qualities of a sports car. The 13B engine used in the RX-7 had been replaced by a turbocharger, and the RX-8's NA design and numerous improvements resulted in higher revs and lower fuel consumption, while at the same time making the engine lighter and more compact, which greatly benefited the car's turning ability and lower centre of gravity. Mazda named the next-generation rotary engine with these improvements the 13B-RENESISE. Although the 13B-RENESISE engine had less power than the turbocharged 13B engine in the RX-7, it successfully improved environmental performance and fuel economy, which had long been regarded as the weak points of the rotary engine. This complete improvement of the engine was also an essential measure to make vehicles with rotary engines compliant with the increasingly strict emission regulations of countries all over the world. In 2003, the RX-8 made its debut. In 2004, the year after its debut, the RX-8 achieved annual sales of approximately 60,000 units, an unprecedented sales record for a sports car. However, it was not only in terms of sales and marketing that the RX-8 excelled. The RX-8's braking and cornering performance were regarded as the best of any Japanese car, and Mazda's engineers succeeded in achieving the seemingly impossible goal of creating a car that was both a family car and a serious sports car. In 2008 and 2010, the racing version introduced by Mazda USA won its class at the Daytona 24 Hours in the USA, beating racing machines developed by Ferrari, Porsche and others.

Uranohoshi Jogakuin is a private school in the seaside town of Uchiura in the city of Numazu, Shizuoka Prefecture. In a small high school in the far corner of Suruga Bay. Nine girls, led by second-year student Chika Takami, stand up with a big dream in their hearts. That is to become the sparkling "School Idols"! If they don't give up, their dream will surely come true. For now, they just aim for brilliance and run through the world with gusto! This is where the girls' 'story of making it happen together' School Idol Project began!

She is good at sewing and is in charge of making stage costumes for Aqours (AQUA). Second-year student at Uranohoshi Jogakuen. She is a member of the swimming club and is a national team level high dive swimmer. Her hobbies include muscle training and cosplay. She has a cheerful and active personality and is the type who acts before thinking. However, among the Aqours members, she has a sensible side. She is also a multi-talented person who is good at cooking and handing out leaflets. She is a childhood friend of Aqours members Chika Takami and Kanan Matsuura. She was invited to join the school idol group Aqours by her childhood friend Chika. She is fond of saying 'Yosoro'.

In charge of music production for Aqours (AQUA). Second-year student at Uranohoshi Jogakuen. Pianist who transferred from Otonokizaka Academy, the alma mater of the school idol group μ's. She has been expected to be a pianist since she was a child, but fell into a slump after a competition and transferred to Uranosei Jogakuen to escape from music. She is quiet, calm and shy. She is also a kind character who never forgets to be attentive to those around her. As soon as she transferred to the school, she was invited by the main character Chika Takami to become a member of the school idol group Aqours, and halfway through she was forced to join Aqours. She is not fond of dogs, and the 'shiitake mushrooms' kept at Chika's house are her natural enemies. She also has a hidden otaku side, as she buys a lot of doujinshi when she goes to Akihabara.

Founder of the school idol group Aqours. Second-year student at Uranosei Jogakuen. Writes the lyrics to the songs sung by Aqours. Her family runs an inn and she is the youngest of three sisters. She decided to form the school idol group Aqours in order to rebuild Uranosei Jogakuen, which is in danger of being closed down due to the declining birth rate. She looks up to Honoka Kousaki, who prevented the closure of Otonokizaka Academy through the formation of the school idol group μ's and their activities. She has a friendly and cheerful personality and is good at paying attention to others. She believes that she has no outstanding abilities or talents, and spends her days in agony, unable to have any dreams or hopes for the future.