Kep1er
Kep1er (; Korean: 케플러; RR: Kepeulleo) is a South Korean girl group formed through the Mnet reality survival competition show Girls Planet 999 in 2021 and managed by Swing Entertainment and WakeOne. The group is composed of nine members: Kim Chae-hyun, Huening Bahiyyih, Choi Yu-jin, Kim Da-yeon, Seo Young-eun, Kang Ye-seo, Hikaru Ezaki, Mashiro Sakamoto, and Shen Xiaoting. They made their official debut on January 3, 2022, with the extended play (EP) First Impact.

Name
"Kep1er" was a name suggested by viewers of Girls Planet 999 through the website Naver. The name is a reference to the planets in the Kepler star systems named after the 16th century astronomer Johannes Kepler.

History
Formation through Girls Planet 999
Kep1er was formed through the Mnet reality survival show Girls Planet 999, which aired from August 6 to October 22, 2021. The show brought 99 contestants from China, Japan and South Korea to compete to debut in a multinational girl group. Out of initially 99 contestants, only the top nine would make the final lineup.Before the show began, several group members had already been active in the entertainment industry. Choi Yu-jin made her debut in the Cube Entertainment girl group CLC on March 19, 2015, with the group's extended play (EP) First Love; she was on hiatus from CLC due to activities with Kep1er until their disbandment. In 2010, Kang Ye-seo was a member of the girl group CutieL before joining Busters from 2019 to 2020.Kim Da-yeon participated in Produce 48 in 2018, representing CNC Entertainment, while Shen Xiaoting participated in Produce Camp 2020, representing Top Class Entertainment. Both were eliminated in the first round, placing 70th and 80th in their respective shows. Mashiro Sakamoto, a trainee at JYP Entertainment from 2016 to 2018, appeared in the first episode of the Mnet reality survival show Stray Kids as part of the female trainee team, but did not progress past the first episode. Following Produce 48, Da-yeon left CNC Entertainment and signed with Stardium Entertainment, only to leave once more after her debut plans fell through. Xiaoting was a competitive ballroom and modern dancer, having won a gold medal in a modern dance sport competition in Shanghai, as well as ranking sixth globally in a British competition.

2021–present: Debut, Queendom 2, Japanese debut and first Japanese arena tour
Kep1er was originally scheduled to debut on December 14, 2021, with pre-orders for their EP First Impact having begun on November 29. They were also initially scheduled to perform at the 2021 Mnet Asian Music Awards on December 11. However, it was announced that the group's scheduled debut had been delayed to January 3, 2022, after one of their staff members tested positive for COVID-19. Their performance at the 2021 Mnet Asian Music Awards was also cancelled. On December 14, it was revealed that group members Mashiro and Xiaoting tested positive for COVID-19 and were announced to have fully recovered on December 26.
On January 3, 2022, Kep1er released their debut EP First Impact, with "Wa Da Da" serving as lead single. On January 10, 2022, Chae-hyun was announced as the new co-host for SBS MTV's music program The Show alongside Ateez's Yeosang and Cravity's Minhee. On January 13, 2022, Kep1er won their first music program award on M Countdown with "Wa Da Da". On February 21, 2022, it was confirmed that Kep1er will participate in the second season of the Mnet reality competition show Queendom, scheduled to premiere in March 2022. On June 20, Kep1er released their second EP Doublast, with "Up!" serving as the lead single. On August 3, Kep1er released their first Japanese single Fly-Up, featuring "Wing Wing" as lead track. It was released on September 7, 2022.  On September 23, Kep1er released the promotional single "Sugar Rush" through Universe Music. On October 13, Kep1er released their third EP Troubleshooter, with "We Fresh" serving as the lead single.On January 16, 2023, it was announced that Kep1er's second Japanese single Fly-By will be released on March 15, 2023, with "I do! Do you?" as the lead track. The group released their fourth EP Lovestruck!, with "Giddy" as the lead single, on April 10.On February 14, 2023, Wake One and Swing Entertainment announced the dates for Kep1er Japan Concert Tour 2023 'Fly-By' which will be held in Aichi and Hyogo.  This marked the first time that the group will hold a Japanese arena tour since their debut. Kep1er successfully performed in Tokyo at Yoyogi National Stadium on May 20–21, Aichi Sky Expo on June 2–3 and at  Kobe World Memorial Hall in Kobe on June 10–11.

Endorsements
On February 15, 2022, Kep1er became models for South Korean cosmetics brand S2ND.

Members
Choi Yujin (최유진) – leader
Shen Xiaoting (沈小婷; 션샤오팅)
Mashiro Sakamoto (坂本舞白; 사카모토 마시로) – co-leader
Kim Chaehyun (김채현)
Kim Dayeon (김다연)
Hikaru Ezaki (江崎ひかる; 에자키 히카루)
Huening Bahiyyih (휴닝바히에)
Seo Youngeun (서영은)
Kang Yeseo (강예서)

Discography
Extended plays
Singles
Promotional singles
Other charted songs
Concerts and tours
Kep1er Japan Concert Tour 2023 'Fly-By'
Videography
Music videos
Filmography
Reality shows
Awards and nominations
Notes
References
External links

Official website
Kep1er at WakeOne