Roots of 4Minute

BtoB is a South Korean boy band formed in 2012 by Cube Entertainment. The group consists of Seo Eun-kwang, Lee Min-hyuk, Lee Chang-sub, Im Hyun-sik, Peniel and Yook Sung-jae. Originally a septet, Jung Il-hoon departed from the group on December 31, 2020.

SS501 is a South Korean boy band that was formed under the management of DSP Media. The group debuted on June 8, 2005, with five members: Kim Hyun-joong, Heo Young-saeng, Kim Kyu-jong, Park Jung-min and Kim Hyung-jun. They debuted in 2005 with the EP Warning, which included their first number one song, "Never Again". In 2007, SS501 entered the Japanese market with the maxi single Kokoro, which debuted at number five on the Oricon chart. The following year, in 2008, they became the first South Korean artists to win the award for Best New Artist at the Japan Gold Disc Awards. SS501 has released two studio albums and seven EPs in Korean, and two studio albums and three EPs in Japanese.

Jussi Sydänmaa is a Finnish guitarist and a former founding member of the rock band Lordi, performing by the stage name of Amen until his departure in May 2022.