2019–2021: Formation, Mada Minu Sekai, and BBB @onefive was formed in October 2019 by four graduating members of the Japanese idol group
Sakura Gakuin, including
Kano Fujihira, who was one of the
kawaii metal band
Babymetal's three rotating "Avengers" support dancers. On October 15, 2019, the group created social media accounts on Twitter, Instagram, and YouTube, but the identities of its members were kept secret. On October 19, 2019, while the members were still in Sakura Gakuin, their identities were revealed during the Sakura Gakuin Festival 2019 at the
Kanagawa Arts Theatre. During the encore of the show, after performing as members of Sakura Gakuin, they performed their debut single "Pinky Promise" as @onefive for the first time. The choreography for the single was created by
Mikiko. "Pinky Promise" was released as a digital single on the following day, October 20, 2019, Shortly after its formation, the group was unable to perform in-person events due to the
COVID-19 pandemic, relying instead on an online presence to hold virtual events. @onefive's first CD single, "Mada Minu Sekai" (まだ見ぬ世界), was released on June 24, 2020. The group also collaborated with
Adobe on a photo collage contest for the single. On June 25, 2020, the first issue of the youth culture magazine
Ite by
Ohta Publishing featured @onefive on its cover, wearing the outfits for "Mada Minu Sekai". A streamed performance was held on July 19, 2020, to commemorate the release of the CD single. In September 2020, the group collaborated with the Japanese glass manufacturer Hario for the accessories worn as part of the outfits for "Shizuku". The concert @onefive Online Live: Blue Winter 2020 took place on December 22, 2020. It was streamed without an in-person audience due to the ongoing pandemic. The members chose to perform a vocal cover of "
Meri Kuri" by BoA, with
Yoshida playing the piano, and a dance to "Snow White Castle" by Yūki Tsujimura. In January 2021, @onefive collaborated with the Japanese fashion brand Apres Jour for the outfits worn in the music video for the song "BBB". The CD single "BBB" was released on March 3, 2021. On November 1, 2021, "Just for You" was featured in the Christmas commercial of the Japanese jewelry brand The Kiss. On November 24, 2021, the digital single "Underground" was released, which marked the first time that the members of @onefive created their own choreography. They were also deeply involved in the production process of the music video, sharing their ideas on hairstyles, makeup, outfits, visuals, and cuts. The participation of the members in "Underground" was documented, with an emphasis on the choreography, in a four-part documentary series released on YouTube, titled
Their Underground (彼女たちのUnderground,
Kanojo-tachi no Underground).
2022: 1518, major label debut, and OshiBudō TV drama On February 2, 2022, @onefive released its first studio album, titled
1518, and pronounced
ichi-go ichi-e. The "18" in the title represented the age that the members would be turning in the year of the album's release. The title track "1518" marked the first time that the members wrote their own lyrics. They also choreographed the entire song. The other songs on the album, though not written by the members, also contain their thoughts and opinions. The music video for "Lalala Lucky" was produced in collaboration with students of
N High School and in cooperation with Adobe. The collaboration highlighted @onefive's desire to be "a group that grows up with the same
generation". The members co-choreographed "Lalala Lucky" with Minako "Maru" Maruyama from
Elevenplay. The four members choreographed "Just for You". Other festivals included Sakae Sp-ring 2022 on June 5, Yatsui Festival 2022 on June 19, and Spark 2022 in
Yamanakako on July 18. It was announced on August 16, 2022, that @onefive had been cast as members of the fictional idol group ChamJam in the live-action television drama adaptation of the manga
If My Favorite Pop Idol Made It to the Budokan, I Would Die, abbreviated in Japanese as
OshiBudō (推し武道). Namely, Fujihira would appear as Maki Hakata, Yoshida as Yumeri Mizumori,
Aritomo as Yūka Teramoto, and
Mori as Sorane Matsuyama. The drama was broadcast for 10 episodes on
ABC TV and
TV Asahi from October to December 2022, and featured "Miraizu" (未来図) as its theme song. @onefive made its major label debut with
Avex Trax on November 6, 2022, when "Miraizu" was released as a digital single. The members participated in planning the stage production, sharing their ideas on matters such as lighting.
2023: OshiBudō film, Chance×Change, and Justice Day The official fan community service of @onefive was established on January 15, 2023, in the form of a subscription-based mobile application called @onefive Premium. In addition to digital membership cards, it would grant access to exclusive events, diaries, videos, ticket pre-sales, and other premium content. The community was named @fifth on March 3, 2023, and serves as the official fan club of @onefive. On May 12, 2023, the live-action film adaptation of the manga
If My Favorite Pop Idol Made It to the Budokan, I Would Die, abbreviated in Japanese as
OshiBudō (推し武道), was released with "Chance" as its theme song. The four members of @onefive reprised their roles from the television drama. The CD single "Chance×Change" was released on May 24, 2023. On August 4, 2023, @onefive performed at the
TGC Teen 2023 Summer fashion festival, which was held at the
Yoyogi National Gymnasium. @onefive participated for the first time in the
Tokyo Idol Festival on August 6, 2023, in
Odaiba. The group had two performances, first at the "Sky Stage" on the rooftop of the
Fuji Television Wangan Studio, and second at the "Heat Garage" at
Zepp DiverCity. The members themselves had previously participated every year in the festival when they were part of Sakura Gakuin. On August 14, 2023, a short film was released for the song "Like A", featuring actor Taisuke Niihara and the members of @onefive. The members were involved in the production from the scriptwriting stage. The film was entered into the TikTok Toho Film Festival 2023. The CD single "Justice Day" was released on August 23, 2023. The group performed at Giga Giga Sonic at the
Makuhari Messe on October 7, 2023. Members Mori and Yoshida also walked the runway as models. In November 2023, @onefive was selected to be the
Generation Z Leader for
Amazon Fashion Japan. The members began modeling for Amazon with seasonal outfits incorporating coats, sweaters, and other winter essentials, while aiming to convey the charm of Generation Z through fashion. November 17, 2023, marked the creation of the group's official characters, or mascots, called @chib15, pronounced
chibi five. Each of the four members designed their own character: Laa the lion by Fujihira, Babu the chick by Yoshida, Zoey the fawn by Aritomo, and Mimi the rabbit by Mori. In the final quarter of 2023, the group held two concerts under the title @onefive Live 2023: No15e Maker. The first concert, subtitled Underground, was held in Osaka at the Yogibo Meta Valley on November 25, 2023. The second concert, subtitled Overground, took place in Tokyo at the Ex Theater Roppongi on December 21, 2023. The two subtitles referred to the process of rising from the underground.
2024: Classy Crush and first nationwide tour On February 23, 2024, @onefive held a virtual party on the Japanese
metaverse platform Cluster as part of the
NTV Imaginarium 2023 metaverse festival, which took place from December 9, 2023, to March 3, 2024. In addition, the members created pieces of
pixel art depicting their @chib15 characters for the festival, which were both physically displayed at the
Museum of Contemporary Art Tokyo and virtually granted as
NFTs. The song "Mr.Gorgeous" was featured in a commercial for
Amazon Prime Video on April 8, 2024. On April 17, 2024, @onefive's second studio album and first major label album, titled
Classy Crush, was released. The album contains songs that depict strong Japanese girls, including its lead song "OZGi", pronounced
ojigi, The ideas and opinions of the members strongly contributed to
Classy Crush. Member Aritomo indicated that the album was more intentional in presenting the messages that they would like to convey through their music, and that they all decided on the track sequence. The song "Love Call" was featured in a commercial for the Japanese jewelry brand The Kiss on August 8, 2024, in which the four members also appeared. On September 1, 2024, @onefive performed at
A-Nation 2024, held at the
Ajinomoto Stadium. @onefive's first nationwide tour, titled @onefive Livehouse Tour 2024 "
Classy Crush", took place between August 17 and September 15, 2024. The group celebrated its 5th anniversary with a concert titled 5555, held on October 19, 2024, at the Shibuya WWW X venue. A variety series centered around the members, titled
15Vibes, premiered on TV Asahi's Logirl on November 7, 2024.
2025: More Than Kawaii and international expansion @onefive's first international performance took place in
Tainan City, Taiwan, at the 2025 Tainan Hao Young New Year's Eve Party on December 31, 2024. Over 100,000 spectators were present at the time of @onefive's performance, during which the group performed "Liar Liar" for the first time, as well as a dance cover of Taiwanese singer
Cyndi Wang's song "Ai Ni" (愛你). In February and March 2025, the members partnered with various stores as one-day store managers to promote their upcoming spring tour, titled @onefive Tour 2025 "
More Than Kawaii", which would begin on March 30. They also rewrote the lyrics of "Kono Mama ja Koware-sō" (このままじゃ壊れそう) and "Last Blue" for the tour. The group's first extended play (EP),
More Than Kawaii, was released on March 26, 2025. It was produced on the concept that, in this world where
kawaii is commonplace, @onefive will not be limited to being only
kawaii. The members were deeply involved in the production of the songs from scratch, putting their real thoughts and feelings into them. They also came up with the lyrics for "Hanamichi" themselves, which were then put together by Yui Mugino. Furthermore, member Fujihira participated as an assistant in the process of choreographing "Sit Down Please". @onefive performed in mainland China for the first time at TIF Asia Tour 2025 in
Shanghai, held at the Bandai Namco Shanghai Cultural Center on June 14 and 15, 2025. The group also returned to Taiwan for the 2025 Taiwan Comic Exhibition, held at the
Taipei World Trade Center on July 25, 2025. On July 26 and 27, the group returned to mainland China for @Jam Shanghai Pop Vol. 1, held at the Bandai Namco Shanghai Cultural Center. @onefive performed for the third time in Taiwan at Trendy Taipei J-pop Night, held at the
Taipei Arena on September 7, 2025. As international performances became increasingly common, @onefive expressed their desire to promote Japanese music and culture abroad, in line with their "Japanese Classy Crush" concept. In July 2025, @onefive collaborated with the American fast-food chain
Taco Bell in Japan to create and promote original menu items by the members, which would be available nationwide from July 14 to September 13, 2025. The song "Tap!Tap!Tap! (TJO Remix)" was featured in a commercial for the Japanese jewelry brand The Kiss on August 8, 2025, in which the four members also appeared. The group performed at the music and fashion event Starrz Tokyo 2025 on September 23, 2025, at the
Nihon Kogakuin Arena. Members Mori and Yoshida walked the runway as models as well. @onefive also performed at the fashion festival TGC Kitakyushu 2025 on October 11, 2025, at the West Japan General Exhibition Center. On October 23, 2025, @onefive was appointed as the official ambassador for the mobile game
Strinova. A new version of "Kawaii Kaiwai" in Chinese, titled "Miāo Miāo Xīntiào" (喵喵心跳, "Meow Meow Heartbeat"), became the theme song for the game. In addition, a music video was released in which the members
cosplay as characters from the game. On November 6, 2025, the group began to host its first regular radio show, titled
Urunemu (うるねむ), on
FM Yokohama. The weekly radio show would continue @onefive's YouTube podcast of the same title, which originally ran for 10 episodes. In December 2025, member Yoshida created new choreography with the assistance of member Fujihira for a jazzy version of "ChocoLove". It was performed on the first day of the @onefive Live 2025 "
Doh Yoh" concerts, which took place at the Hulic Hall in Tokyo on December 20, 2025, and at Bigcat in Osaka on December 26, 2025.
2026–present: Doh Yoh, Road to Budokan, and Sakuraization The group's second EP,
Doh Yoh, was released on January 15, 2026. It was produced with the cultural theme of
dōyō, which are popular Japanese children's songs. For example, the
dōyō "
Alps Ichiman Jaku", "
Momotarō", and "
Mori no Kuma-san" are reimagined as
Afrobeat,
hip-hop, and
hyperpop songs in "Alps Vibes", "Kibidango", and "Magical Irony", respectively. "Magical Irony" entered the
Billboard Japan Heatseekers Songs chart. On January 30, 2026, a micro-drama was released for "Netsukikyū", featuring actor Robin Furuya and the members of @onefive. @onefive officially launched its "Road to Budokan" initiative on February 8, 2026, with plans to perform at the Nippon Budokan by spring 2027. The goal was set for two reasons: first, due to the influence of playing the role of ChamJam in
If My Favorite Pop Idol Made It to the Budokan, I Would Die; and second, since people of the same birth year as the members, 2004, would be job hunting and starting work after graduating from higher education around that time. The official member colors of @onefive were announced on March 25, 2026, with red for Fujihira, green for Yoshida, purple for Aritomo, and pink for Mori, which correspond to their favorite colors. The official colors exist in addition to their official roles, which are Fujihira as the "performance leader" (パフォーマンスリーダー), Yoshida as the "
shoken killer" (初見キラー), Aritomo as the "
datsuryoku-kei onē-san" (脱力系お姉さん), and Mori as the "
azato rapper" (あざとラッパー). == Artistry ==