Lee Seung-jun, known mononymously as Seungjun and formerly known as J-Us, is a South Korean singer and lyricist under KI Entertainment. He is a member of the boy group ONF and its OFF team sub-unit.
Lee Seung-jun, known mononymously as Seungjun and formerly known as J-Us, is a South Korean singer and lyricist under KI Entertainment. He is a member of the boy group ONF and its OFF team sub-unit.
![온앤오프(ONF) CONCERT [SPOTLIGHT:THE HIDDEN SHADOW] NIGHT 1](https://image.tmdb.org/t/p/w300/zyN3yVwFR1NoZGgxd77aZ4etce7.jpg)
![온앤오프(ONF) CONCERT [SPOTLIGHT] IN SEOUL NIGHT 1](https://image.tmdb.org/t/p/w300/6DhiTgCYAg09SDRLGCktfByp6xD.jpg)
![ONF 2021 LIVE CONTACT :: CODE #1. [REVERSE]](https://image.tmdb.org/t/p/w300/4wjPi5x2igYJI9jrbE5QcJhSW8X.jpg)
![온앤오프(ONF) CONCERT [SPOTLIGHT:THE HIDDEN SHADOW] NIGHT 2](https://image.tmdb.org/t/p/w300/whume1STRxwi0EVBYU8ZMk669nG.jpg)
![2025 ONF CONCERT [THE MAP:STRANGER’S PATH]](https://image.tmdb.org/t/p/w300/pvF5lXWpkD3HuDDJSXeXtKXlZD1.jpg)
![2026 ONF CONCERT [THE MAP: BEYOND THE HORIZON]](https://image.tmdb.org/t/p/w300/vQmZPhEa8KrUCwrqRqMpl9pube9.jpg)
![ONF [FOCUS ON AND OFF]](https://image.tmdb.org/t/p/w300/Au7UBGXv8opgUV1V7lUzl4Bu2i2.jpg)
