Origins & Roots Born in the coastal city of Busan, South Korea, Lee Donggun grew up with a deep-seated passion for movement and expression. His early childhood was defined by a curiosity for the arts, eventually leading him to dedicate his formative years to the rigorous discipline of dance and vocal training.

Training & Trials Donggun's journey into the spotlight began with intensive training at agencies like Bill Entertainment and Great M Entertainment. He navigated the high-pressure environment of K-pop trainee life, honing his skills in flexibility and performance, which would later become his signature traits.

Breakthrough His national breakthrough arrived in 2023 when he competed on MNET’s survival show Boys Planet. Despite his elimination in episode 8, the experience provided him with a global platform and a dedicated fanbase, marking the beginning of his professional ascent.

Ascension Following his departure from major agency structures, Donggun embraced independence. In 2026, he rebranded with the stage name 'Rheo'—symbolizing his philosophy of being part of the 'flow' of art—before officially joining the boy group X_ON, signaling a new chapter in his career.

Legacy Beyond the stage, Donggun is known for his resilience and personal growth. Whether through his love for his cat, Yojeong, or his multilingual interactions with fans, he continues to build a legacy rooted in authenticity and artistic evolution.