CIX

CIX (씨아이엑스; Complete in X) is a four-member South Korean boy group under C9 Entertainment. Originally debuting as a five-member act on July 23, 2019, with the EP "Hello Chapter 1: Hello, Stranger," CIX have built a reputation for dark, theatrical concepts and genre-blending production. Current members include BX (leader), Seunghun, Yonghee, and Hyunsuk, following Jinyoung's departure in August 2024 to fulfill military service.

The group's pre-debut history reads like a survival show compendium. Bae Jinyoung finished tenth on Produce 101 Season 2 and debuted with Wanna One. BX and Seunghun competed on YG Treasure Box for what would become TREASURE; both were eliminated in the finale. BX also placed ninth on Mix Nine. These shared experiences shaped CIX's underdog identity from the start.

Their debut was fast and decisive. "Movie Star" debuted CIX to Korean audiences in July 2019; six days later, they took their first music show win on The Show. They signed with Warner Music Japan in August and released a Japanese version of their debut EP by October. The "Hello" tetralogy concluded with "Hello Chapter Ø: Hello, Strange Dream" in February 2021, followed by the "OK" series.

Their 2025 comeback arrived with the EP Thunder Fever in January, featuring the title track "THUNDER." The group announced their 4th Concert THUNDER FEVER world tour that same month. They are labelmates with rising rookie group NAZE.