There's a plethora of boy groups in K-pop today and it's all thanks to the originators, SoBangCha.
SoBangCha made their debut in 1987 under Daesung Ent (later DSP Media) with the three original members: Taekyung Kim, Wonkwan Jung, and Sangwon Lee. Their original name was Butterfly Sin in the Cosmos but during a performance at a nightclub in Seoul, the nightclub owner had a difficult time pronouncing their name, so they decided to name themselves firetruck or SoBangCha.
After debuting with the song "Please send this message to her," they quickly jumped to stardom and gained a legion of screaming female fans. Much like K-pop fans today, it had a profound effect when their fans were first exposed to the music. After nothing but mostly trot music, this was the first time these girls were exposed to stylish men (at the time) with intricate choreography and a pop sound.
After becoming stars, there was some friction in the group and member Sangwon Lee decided to leave the group. SoBangCha looked for a replacement and found one in member Gunwoo Do. They continued to release hit after hit without missing a beat after the member change.
SoBangCha unfortunately broke up in 1990 as they had more friction in the team. The group decided to get get back together in 1994 but by then, the Korean music landscape had already changed dramatically and they didn't have much success. They broke up again in 1995. Since then they've released more music in 2005 and 2012 but unfortunately received little attention. Member Sangwoon Lee was also accused of raping a young girl in June of 2000 but he was later found to be not guilty after a court trial and investigation.
SoBangCha had a profound impact on Korean music being the very first boy group. Though their popularity has waned over the years, hopefully their legacy will never be forgotten.