The song that would become the most-streamed Japanese track in history began as a secret demo titled Kyūkyoku no Ogi, or Ultimate Move, written by producer Ayase in 2022. Before it was ever called Idol, the track was a Vocaloid experiment inspired by the fighting game character Chun-Li, depicting a girl who was the strongest and unbeatable fighter with a dark side. Ayase, a self-described super huge fan of the manga Oshi no Ko, had already written this demo before the anime adaptation was even announced in June 2022. When the offer to perform the opening theme arrived, he did not discard the original idea but instead interwove the demo with a new composition to create the final version. This transformation turned a simple Vocaloid track into a complex three-minute-and-thirty-three-second masterpiece that combines pop, hip-hop, rock, and video game music to depict the two-faced nature of a star in the Japanese idol industry. The song was released as a single on the 12th of April 2023, serving as the opening theme to the first season of the anime Oshi no Ko, and it immediately began to dismantle the boundaries between the idol's public perfection and private desperation.
The Secret Behind The Smile
The lyrics of Idol delineate multiple different perspectives on the anime's central character, the idol Ai Hoshino, revealing a story that is far more complex than a standard pop song. The first part expresses the eyes of outsiders, fans and media, who see her as a perfect liar and a genius idol who silences the world with an invincible smile. In the first verse, Ai answers fans who ask how she can love someone when she no longer distinguishes between truths and lies, while the chorus speaks of her perfection and how she captivates everyone with her smile and saying I love you even though it is all a lie. The second part sarcastically tells the story of the girl group B-Komachi's other members' jealousy of the absolute center, Ai, as they were relegated to her supporting roles as backup dancers. These members are unable to tolerate Ai's whining and showing her true feelings, desiring for her to always be perfect and stronger than anyone else. The third and final part depicts Ai's point of view of her reasons to lie, greed, and imperfection, as she hides the secret of being the mother of twin children, Ruby and Aquamarine. She is convinced of the strength of her love and believes that the singing and dancing while hiding the truth is metaphorized as Mary, the mother of Jesus, hoping someday her lies become true and she does not lie about loving her children.
The Keypad Code
The source of Idol is a short story written by Oshi no Ko writer Aka Akasaka titled 45510, which was first published via the Weekly Young Jump website on the 13th of April 2023, shortly after the anime's first episode televised premiere. The title refers to the initials of the manga's fictional idol girl group B-Komachi founding members: Takamine, Nino, Ai, and Watanabe, when typing on a telephone keypad. Each number corresponds when feeding kana inputs, with 4 representing Takamine, 55 representing Nino, 1 representing Ai, and 0 representing Watanabe. The story is told from the perspective of an unidentified former founding member of B-Komachi, who discovers the livestream of their former groupmate and center, Ai Hoshino, 16 years after her death. The video showed Ai talking to her fans, making her reminisce about her jealousy. After the video ended and she could not find more videos, the former member decided to try logging in to B-Komachi's blog, which was operated by four founding members, whose password was 45510. She found Ai's unpublished posts, written about her negative feelings and her desire to return to the past. The former member decided to delete the posts because she did not want to show Ai's weak side to everyone, even though she disliked Ai, the protagonist also respected Ai as a perfect and ultimate idol.
Idol is driven by bright and poppy, idol-like bubblegum, and reign of the king atmosphere-like sounds, but it also includes dizzying transitions such as jazz-funk slap bass, gritty sub-bass, orchestral and electronic-sounded chorus, and dark trap metal-like melody. According to Ayase, who solely wrote and produced the song, the production of Idol was inspired by strong lows by American musician Ghostemane and bass guitar played during the live performance of Indonesia rapper Rich Brian at the 2022 Head in the Clouds Festival. The song features uncredited background cheering shouts by Akihabara-based B-boy group and YouTuber Real Akiba Boyz, and gospel-styled background vocals sung in English for praise idol. The Japan Times Patrick St. Michel described the song as a mix of varied influences that draws from Akihabara livehouses and Atlanta hip-hop, that is connected by a piano dash that has come to define Ayase's production. Music critic Hwang Sun-up noted that Idol reflects a lot of K-pop elements in terms of sound and composition, citing Blackpink's How You Like That for grand intro, and Nmixx's O.O for mixed structure. Ikura's vocals in the song are described as alternating between cutest idol in the world-like sweet and clear voice and frenzy and introspection with deep sarcastic snarls and K-pop-esque rapid-fire trap beat-styled rapping.
The Billion Stream Record
Idol became the fastest song to reach 100 million on-demand streams in Japan within five weeks, breaking the six weeks of Official Hige Dandism's Subtitle and BTS's Butter. It later broke a string of records for the fastest song to accumulate 200, 300, 400, 500, 600, 700, 800, 900 million, and one billion streams within 137 weeks. The single became the first-ever song to reach one billion streams in Oricon history, and the second song on the Billboard Japan after the duo's own Yoru ni Kakeru. As of April 2024, the Recording Industry Association of Japan certified Idol double platinum for digital sales, exceeding 500,000 units, and diamond for streaming, surpassing 500 million times. The latter marked the song as the fastest song to achieve diamond certification in the RIAJ history within 295 days after the single release. The Japanese Society for Rights of Authors, Composers and Publishers reported that Idol was the highest earned royalties in Japan for two consecutive years, from 2023 to 2024. Globally, Idol became the first Japanese-language song to top the Billboard Global Excl. US, and was marked at number seven on the Billboard Global 200, the highest peak by a Japanese act at that time. According to the International Federation of the Phonographic Industry, the single was the 19th best-selling song in 2023.
The Stage of Legends
An accompanying music video for Idol premiered on Yoasobi's YouTube and Ayase's Niconico channels on the 13th of April 2023, at 0:30 JST, shortly after Oshi no Ko televised premiere. Directed by Naoya Nakayama, and produced by Doga Kobo, who also was in charge of anime production, the visual features the same animated visuals as the anime, depicting the bright and dark symbolism of Ai Hoshino, and her twin children, Aqua and Ruby. In the end, it shows Aqua and Ruby as high school students watching her mother Ai performing on television, which does not appear in the anime. The director described the scene as the world that Ai wanted to see. The Idol music video became the duo's fourth music video to accrue 100 million views, following Yoru ni Kakeru, Kaibutsu, and Gunjo, as well as the fastest music video to reach this mark by any Japanese act within 35 days, surpassing the 62 days of NiziU's Make You Happy. It became the 2023 most-viewed music-related video on YouTube in Japan, and has gained over 600 million views as of May 2025. The English version's music video was released later in conjunction with the song on the 26th of May 2023.
The Final Battle
The first Japanese televised performance of Idol took place at the 74th NHK Kohaku Uta Gassen, featuring selected members of the participated Japanese and Korean idol groups, Ano, Kanna Hashimoto, Real Akiba Boyz, and Avantgardey, which was considered to be the most attracted show of the event. Alongside the duo and the band members, the show featured numerous guests, beginning with dance group Avantgardey and B-boy group Real Akiba Boyz. Following the first verse, selected members from that year's ten participating Japanese and Korean idol groups performed one after another. Next, singer Ano and actress and the program's host Kanna Hashimoto, former member of idol groups You'll Melt More! and Rev. from DVL, respectively, who both gained attention from fan-taken photos comparison of the two during their idol career, nicknamed the final battle between angel and devil, appeared and did their viral posture. The show concluded by all performers performing together. Despite the lowest rating since 1989, the Idol show was considered to be the highlight and the most attracted attention of the event, especially online. The Japan News Yohei Kitagawa praised the duo having a strong and unrivaled presence and unifying force for all of the other stars on stage. The partial performance uploaded on NHK Music YouTube channel received 11.28 million views before it had been made private, the most among the channel's video.
The Internet Phenomenon
In late April 2023, shortly after Idol release, a recreated video of the title sequence of Oshi no Ko connecting to the title sequence of Shin Getter Robo vs Neo Getter Robo, in which Idol was changed in the middle of the chorus to JAM Project's Storm, Kimi wa kanpeki de kyūkyoku no Getta, went viral and became an Internet meme. This meme resulted in Storm being officially released to the music streaming services on the 3rd of July 2023. The phrase Kimi wa kanpeki de kyūkyoku no Getta won Gold Award at the 2023 Internet Buzzword Award, and Niconico Award and second place of Top 20 Words Award at the 2023 Internet Buzzwords 100. Fan-made choreography created by dancer and singer Kotaro Ide and wotagei-styled dance of Idol also gained attraction as an Internet challenge on video hosting service TikTok, covered by Japanese and Korean idols among others. As of December 2023, the song garnered 7.9 billion views on TikTok. Idol was the most-searched and the third most-humed-to-search song on Google in 2023. The song was chosen as the best anime song of the Reiwa era by the survey from 10,000 people by TV Asahi television special 1 Man Nin ga Erabu! Tsui ni Kettei! Reiwa vs Heisei vs Shōwa Anison Ranking, and the second-most voted best anime song on the survey by 1,740 overseas anime fans from the TV Asahi television special Gaikokujin ga Gachi de Tōhyō! Sekai Anison Sōsenkyo, behind only Yoko Takahashi's A Cruel Angel's Thesis.