Kim Jun-seo first performed with 1THE9 following the reality competition Under Nineteen. He later joined WEi’s original six-member lineup and took part in its music and performances from the October 2020 debut through January 2025.

In May 2025, his agency announced a halt to his WEi group activities. He later participated in Boys II Planet and earned a place in ALPHA DRIVE ONE, debuting as a member of that group in January 2026 under WAKEONE.

JUNSEO’s current work with ALPHA DRIVE ONE is a separate group career, not a solo recording project. This profile preserves his WEi history while clearly describing the ongoing hiatus in WEi promotions.