Sandeul (산들)

Nearly 15 years into a career that has moved between pop stages and theatre houses, Sandeul has built a reputation as one of K-pop's more quietly tenacious performers. As the main vocalist of B1A4, the WM Entertainment group he has been part of since debut, he established the vocal foundation the group's sound rested on — and then, rather than coasting on that identity, spent the years that followed testing himself in the considerably less forgiving world of Korean musical theatre.

From idol stage to theatre floor

Born Lee Jung-hwan on March 20, 1992, Sandeul entered the industry as B1A4's lead voice, a role that placed him at the centre of the group's melodic output across more than a decade of activity. Where many idol vocalists treat musicals as a prestige side project, Sandeul pursued the discipline with enough seriousness that it became a parallel career in its own right — one he has spoken about with an unusual degree of candour about its costs.

A performer who audits himself

In interviews conducted ahead of his appearance in the 10th-anniversary cast of the musical Death Note in early 2026, Sandeul offered an account of his theatre work that was notably free of the promotional gloss typical of idol press cycles. Describing nearly 15 years of musical experience, he acknowledged that praise, for him, converts almost immediately into pressure: "For me, praise is soon doubt." The admission reflects a self-critical discipline — he described checking audience reactions in detail after each performance, and framing negative responses not as attacks but as data. "If they curse, I have to reflect, what can I do?"

He also disclosed that the transition into musical performance had not been seamless. Despite arriving with main-vocalist credentials from B1A4, he described a period of repeated failures in the theatre context that he said had measurably affected his confidence. "My self-esteem has dropped a lot," he said — a statement that, in the context of Korean idol culture's emphasis on polished public presentation, carried some weight. Alongside that, he acknowledged a persistent anxiety about live audiences while being equally clear that it had not been sufficient reason to stop. The tension between discomfort and compulsion, as he described it, is precisely what keeps him performing.

Standing

What emerges from the available material is a portrait of a performer who has declined to let an established idol identity set a ceiling on his ambitions, while being candid about the gap between aspiration and execution. The Death Note anniversary casting, and the self-scrutiny he brought to discussing it publicly, suggests that after nearly a decade and a half in the industry, Sandeul remains more interested in the difficulty of the work than in the security of what he has already proven.