Yash Kumar started as a music composer in 2000. His debut album was Yo Sansar where he composed all songs. "Behal Bhayo Zindagi Yo" became an instant hit from the album. Even though he released his second album Umer in 2001, Yash Kumar rose to fame for his third solo album Reason. The song "Maile Chhoyeko Paani Chaldaina" became the chartbuster song of the year which bagged him several awards. He again released his fourth album Tirkha which became another successful album of his career with a popular of a song "Ma Aafnai Aaganma Inar Banauchhu" from the album. He release his fifth album Timi in 2005 which was a medium hit followed by his sixth album Na Rune Aakha Haru. Even though he modeled for most of his music videos, he debuted in movie Bato Muniko Phool in 2010 as a lead actor. Bato Muniko Phool was the highest budget movie in Nepal of the year.[7] He later acted in the movies Veer, Aadhi Bato, Baato Muniko Phool 2 as a lead actor. Yash Kumar last appeared in the movie Tshering in 2018, in which he debuted as a director as well.