Kim Min-jae trained as an idol for years before becoming an actor. He is known by his rap name He made his acting debut in 2014 through the South Korean-Vietnamese co-production drama Forever Young. In 2015, he auditioned for Mnet’s Show Me the Money 4, where he showcased his powerful rapping skills. However, he got eliminated during the second round of the program. In 2016, he was cast in the SBS series Romantic Doctor Teacher Kim, which won him the New Star Award at the SBS Drama Awards. He also scored a Best New Actor for TV nomination at the 53rd Baeksang Arts Awards for his work in the drama. In 2017, he became part of the KBS2 series The Best Hit, in which he was nominated for Best New Actor at the inaugural The Seoul Awards. In 2018, he starred in the MBC drama The Great Seducer. His performance in the series earned him two Best New Actor nominations. In 2019, he landed his first leading role in the JTBC sageuk Flower Crew: Joseon Marriage Agency. In 2020, he reprised his role in Romantic Doctor Teacher Kim 2. That same year, he headlined the SBS romantic drama Do You Like Brahms, in which he earned an Excellence Award at the SBS Drama Awards.

Kim Min-jae studied composition and piano in his younger years. He personally played many of the piano pieces in Do You Like Brahms, where he portrayed the role of a world-famous pianist. He is close friends with BTS’s V.