Woosung is the first member of The Rose to dive into multiple solo projects outside the band. While Dojoon, Hajoon and Taegyeom took a two-year break for their mandatory military service as Korean citizens, Woosung, the only Korean-American in the group, started working on his own music. He released his pre-single Lonely on July 19, 2019, and then dropped his solo project Wolf on July 25, 2019.

Woosung has released a number of solo projects, including his debut full-length album, Genre, in 2021, followed by his EP Moth in 2022. Additionally, he served as an opening act for Epik High during their U.S. tour in the same year.

He has contributed his vocal talents to various K-drama original soundtracks and was featured on the song Sriracha by The Attire. In 2023 he was featured on the track Snooze by Agust D, which also included the late composer Ryuichi Sakamoto.

In 2023, it was formally announced that Woosung had been cast in the Netflix animated series Jentry Chau vs. The Underworld, as ‘Kit’, marking his first role as a voice actor.

His most recent project 4444 was released on October 4, 2024. In the same month, he embarked on his B4 We Die World tour and hosted his exclusive VIP dinner event, The Woolfpack Feast, in both New York City and Los Angeles as an accompaniment to the tour.