OnlyOneOf

In December 2016, Blockberry Creative announced the debut of a new group called "8x8x8", which would follow up from the ongoing debut project of girl group LOONA. This name originated from the fact that they would debut on August 8, 2018.[3] Along with this, Blockberry Creative also announced they would begin holding auditions from January 2017 to determine the lineup of this group.

The next year, in April 2017, the first of these trainees was revealed, with the appearance of leader Love in the music video for ViVi of LOONA's solo album. Later, in September 2017, 8x8x8 was once again mentioned briefly in the description of LOONA ODD EYE CIRCLE's music video for 'Girl Front', stating that the B-Side "Chaotic" on their mini-album "Mix & Match" had 'initially been chosen to be the title track for 8x8x8.[4]

However, as no further mention was made of the group after this point, with LOONA releasing their lead single for their debut album on August 7, 2018, it led many to believe that 8x8x8 had either been delayed or shelved, in order for BlockBerryCreative to prioritize their main group.

On April 30, 2019, however, Jaden Jeong (OnlyOneOf's creative director) posted the logo of OnlyOneOf to his Instagram,[5] announcing that the group would 'finally debut in May'. It has therefore been speculated that, after the departure of Jaden Jeong from Blockberry Creative, the trainees who had been selected for the lineup of "8x8x8" were transferred to 8D Creative's RSVP label.

With the release of the first group image a day later, as well as the music video teaser for "Savanna", familiar faces were soon spotted among the members. One of these was Love, who, as previously mentioned, had appeared in LOONA member ViVi's debut music video "Everyday I Love You", as well as starring as one of the male leads in the webdrama "Woomanna".

It was revealed on May 24, 2019, that the group would debut with two title tracks: fan title "Savanna" and pop title "time leap", as part of a mini album titled "Dot Point Jump".[6] Four days later, on May 28, 2019, the music videos for both title tracks "Savanna" and "time leap" were released, with each of the other tracks being unveiled individually once the hashtag '#OnlyOneOf' had been used 5,555 times on Twitter. These milestones were reached over the following days, with the full mini album being available for purchase as of June 13, 2019.

On October 4, 2019, the first teaser for their second mini album "Line Sun Goodness" was uploaded to YouTube, announcing that their first comeback would take place in the same month. A week later, the individual teaser photo for YooJung was released, revealing the album would be released on October 30, 2019. OnlyOneOf made their first comeback with the title track "Sage". Due to technical difficulties,[7] the music video was not released until 3 days later, on November 2, 2019.

On January 23, 2020, the first teaser for unknown art pop 2.1 was released, and "dOra maar" was released a week later. To celebrate this, OnlyOneOf held a contest for participants to write English lyrics for "dOra maar", with the winner receiving a cash prize of $100,000, as well as having their version released as the official international version at a later date.[8]

On April 30, 2020, it was announced that there would by three separate releases for OnlyOneOf in the works "Produced by [ ] series". The first release, "Produced by [ ], Pt. 1", was produced by GRAY, BOYCOLD, Cha Cha Malone. The first teaser was released five days later on May 4, 2020. On May 21, 2020, the single album with the title track "Angel" was released.

On June 15, 2020, the first teaser for the second release "Produced by [ ], Pt. 2", was released. On August 7, 2020, the first individual teaser of Yoojung was released. Following Yoojung, every member's individuals teasers were released in the following days. The second release was produced by GroovyRoom, Samuel Seo, and Jr Groove. The second single album was released on August 27, 2020 with the title track "a sOng Of ice & fire".