In 1989, following the introduction of the consumption tax in Japan The taxation system for vehicles in Japan was reviewed and the tax burden on vehicles falling under Japan's own kei car standards increased. As a result, the Japanese kei car market was shrinking in the early 1990s. To break out of this situation, Suzuki introduced the Wagon R (first generation CT21S/51S/CV21S/51S models) in Japan in 1993 as an innovative minicar with a new concept based on the American minivan. Before the introduction of the Wagon R, minicars, which were restricted by Japanese regulations in terms of body size and displacement, were generally superior in terms of maintenance costs and manoeuvrability, but had limited interior space. In order to improve the interior space, which had been a disadvantage of minicars, Suzuki increased the overall height of the body significantly compared to conventional minicars to create more interior space, and installed a double-layer floorpan to provide anti-vibration and soundproofing measures, and also used the higher seat position as a counterbalance to improve the occupants' seating posture. Various innovations were attempted in terms of packaging and mechanisms, such as making the occupants' seating posture more upright to create more leg room. The first generation Wagon R, with its ease of use and good space utility, won the support of a wide range of users in Japan and quickly became the best-selling car in the country. On the other hand, the success of the Wagon R spawned a number of strong rivals in the Japanese market with similar concepts to the Wagon R, such as the Daihatsu Move. As a result, the Wagon R's followers, the high wagon-type minicars, became the majority in the Japanese market, where minicars account for close to a majority of sales, and had a significant impact on the way Japanese car manufacturers produced their cars. In order to compete with its powerful rivals, Suzuki continued to prioritise the introduction of the latest Suzuki technology at each model change, and despite numerous model changes, the Suzuki R has firmly established its position as Japan's best-selling car. This is the third-generation Wagon R, which was launched in 2003. The platform was renewed from the previous generation Wagon R, and new Suzuki technologies were actively introduced, such as the use of a direct injection turbo engine.

Otonokizaka Gakuin, a traditional school located between Akihabara, Kanda and Jimbocho, is on the verge of consolidation. Nine girls, led by second-year student Kosaka Honoka, rise up to meet the school's crisis. What we can do to protect our favourite school. ...... That is to become an idol! Become an idol to publicise the school to the world and increase enrolments! This is where the girls' 'story of making it happen together' School Idol Project began!

The universe's NO.1 idol. Head of the Otonokizaka Academy Idol Club, to which μ's belongs. 3rd year student. In the past, she founded and served as the head of the idol research club, She is an idol geek from the bottom up. She is more passionate and devoted to idols than anyone else, Before joining μ's, she studied as a school idol on her own. Therefore, she has determined the direction of μ's as a school idol by providing guidelines for the other μ's members, who were not originally familiar with the situation of school idols. She is also in charge of comedy in μ's and plays the role of a comedian for the other members. She is the mother of two younger sisters and a younger brother, and looks after them on a daily basis. She is a good cook. Her signature phrase is 'Nikki-nikoni-nikoni-'.

Third-year student at Otonokizaka Academy. Vice-president of Otonokizaka Academy and a good adviser to the other members of μ's. She has strong spiritual sensitivity and is good at fortune-telling. When she was a child, she often had to change schools due to her parents' work, which meant that she did not fit in well at school and did not have any friends for many years. Therefore, it has long been her wish to make friends in high school. She is more caring than most and has been providing advice and support for Honoka Kousaka's plan to prevent the consolidation of Otonokizaka Academy since before she joined μ's. She is also a member of the 'Kousaka Honoka' group and has been a member of the 'Kousaka Honoka' group for many years. The name of Otonokizaka Academy's school idol group, 'μ's', was the brainchild of Nozomi, The group name "μ's", the school idol group of Otonokizaka Academy, was the brainchild of Nozomi.

Third year at Otonokizaka Academy. She is the student council president at Otonokizaka Academy and a dance coach for μ's. She grew up in Russia, the home of ballet, and was educated as a gifted ballet dancer from an early age. Her dancing ability is at a professional level. At first Eri was sceptical about Honoka Kousaka's plan to increase the number of applicants to Otonokizaka Gakuin and prevent the consolidation of Otonokizaka Gakuin through the publicity effect of School Idol, but she was inspired by Honoka's enthusiasm and joined the group herself as a member of μ's. She was also inspired by Honoka's enthusiasm and decided to join as a member of μ's herself. Her grandmother is Russian and she is fluent in Russian. Her habit is to say "Harasho" in Russian.