[1] The group consists of the following members, Eun Ji-won, Lee Jai-jin, Kim Jae-duck, and Jang Su-won.

Eun Ji-won was scouted at a nightclub by DSP Entertainment's CEO while studying abroad in Hawaii, along with Kang Sung-hoon.

The agency originally planned to debut Eun Ji-won and Kang Sung-hoon in South Korea as a duo, but with the success of SM Entertainment's male idol group H.O.T., the agency shifted gears to debut a six-member male idol group instead.

Shortly afterwards, Sechs Kies made their much anticipated comeback in October on KMTV's Recharge 100% Show and began promotional activities for their second album release.

They quickly began promoting the album's title track "Chivalry" (기사도) on various music programs, which gave the group their first number one spot on SBS Inkigayo on December 7.

[5][6] On December 21, Sechs Kies held their first concert in Seoul at the Sejong Center for the Performing Arts; tickets were reportedly sold out within five hours.

After wrapping up their second album promotions in February, they began a spring nationwide tour, including concerts in Busan, Ulsan, Gwangju, and Daegu.

On May 5, Sechs Kies performed the musical in front of President Kim Dae-jung at Blue House to celebrate Children's Day.

Sechs Kies held consecutive wins for the title track "Road Fighter" on SBS Inkigayo and KBS Music Bank in July and August.

They also won for the number one spot on SBS Inkigayo and KBS Music Bank for the follow-up track "Reckless Love" (무모한 사랑) in September and October.

With the huge success of the song, "Couple", Sechs Kies won the 9th Seoul Music Awards Daesang along with rival boy group H.O.T.

On November 30, Sechs Kies participated in the 1st Korea China Music Festival, co-hosted by KBS and CCTV in Beijing.

On February 28, Sechs Kies's Seoul Concert was held in Olympic Gymnastics Arena; tickets were reportedly sold out within a few hours.

[20] On May 31, Sechs Kies released Blue Note, a compilation of "Best Of" songs that served as a farewell album to fans.

In August, the members of Sechs Kies self-released one final track and music video titled "Thanks" for their fans, which was uploaded online.

[21] On April 14, 2016, as part of the popular Korean variety show Infinite Challenge, Sechs Kies re-united through a guerilla reunion concert at the Seoul World Cup Stadium, which was attended by approximately 6,000 fans who were alerted of the concert only five hours before it was held.

Sechs Kies held their first national concert tour since their reunion, titled "Yellow Note", from September 10 to January 22, 2017.

The last two concerts, named "Yellow Note Final in Seoul", were held on January 21 and 22 at the Jamsil Indoor Stadium.

[41] As part of their 20th anniversary celebrations, a Sechs Kies exhibition entitled "Yellow Universe" ran from April 28 to May 28, showcasing artwork by Lee Jai-jin, collected items from the band's earlier active years, as well as contents from their comeback.

[60] Sechs Kies performed as the closing act at the Busan One Asia Festival (BOF) opening ceremony on October 22.

[62][63] On January 17, it was announced that YG Entertainment had successfully registered "Sechs Kies" with the Korea Intellectual Property Rights Information Service (KIPRIS) as an official trademark on April 24, 2017, allowing Sechs Kies members to exercise exclusive rights to the band name.

[65] The film release was officially announced on January 5.The documentary follows Sechs Kies as they prepared for their fifth studio album Another Light; it was filmed using ScreenX technology and opened in select CGV theaters on January 18 in Seoul, Incheon, Jeju, Changwon and Yongin.

[74] The group later performed without Sunghoon on October 14 of that year, where they confirmed they would soon come back, and were in the midst of picking new songs for the album.

During the front yard live on the recording day of 3 meals for four, Yoo Hee-yeol and PD Na Young-suk made a pledge, but Yoo Hee-yeol made a pledge to let Sechskies come to the antenna and record a ballad song if the number of antenna music subscribers exceeds 150,000.

The number of subscribers to Antenna Music exceeded 150,000, so Yoo Hee-yeol decided to give Sechskis a new song.

In addition, it was mentioned that the related contents would be broadcast on January 22 (Fri), 2021 with the title of Don't Look Back,[80] with a five-minute broadcast and the subtitle as : Yoo Hee-yeol x Jekki decided to sing a ballad as a pledge, but somehow, things got bigger and a new song was made, and a song containing the feelings of all of us came out.

Lee Jai-jin mentioned that what Sechs Kies members wanted was to change their agency and not disband at a Korean variety show in 2005.

[84] At a concert in 2015, Kang Sung-hoon stated that Sechs Kies seems to have left a strong impression for having disbanded at the peak of their career.