23 years old. Leader, sub-vocalist, and main dancer (dance machine) of the three-member co-ed dance group 'Triangle'. He introduces himself as the 'Dancing Machine (DM)' and performs breakdance by throwing his whole body and head onto the floor, whether it's a stage or dirt ground. He is rivals with Choi Seonggon, a ballad singer who was pushed back by Triangle. Their songs include 'Love Is' and 'Shout It Out'. They are rookies who recently debuted. His representative color is red. Member of Triangle.

22 years old. Center and main vocalist of the three-member co-ed dance group 'Triangle', who once dominated the music scene. Her nickname is 'Absolute Charm'. In front of the public and broadcasts, she shows a pure and refreshing image, but in reality, she is a character with a dual charm who hides a bold girl-crush nature and toughness. Their songs include 'Love Is' and 'Shout It Out'. They are rookies who recently debuted. Her representative color is green. Member of Triangle.

21 years old. A rapper with unexpected charm. The third member. He has terrible rapping skills, but his passion is on the level of Mansour. He shows extreme persistence and sincerity toward rap and music, to the point of infinitely repeating his eccentric signature rap lyric: "Gu Sanggu forward, Gu Sanggu backward." He barely has any parts. Their songs include 'Love Is' and 'Shout It Out'. They are rookies who recently debuted. His representative color is blue. Member of Triangle.

26 years old. An ill-fated prince of ballads who has remained at number 2 on the charts for 39 weeks, pushed aside by his rivals, the three-member co-ed dance group 'Triangle'. On stage, he is a 'boyfriend for your ears' who sends faint and pure gazes, but in reality, he has a hot-tempered personality that leads to various rumors. His representative song is 'I Like You'.