Ha Jun Seok is a South Korean singer and former member of ULALA SESSION (울랄라세션) and sub-unit ULALA PRAISE (울랄라 프레이즈). He graduated with a bachelor’s degree in Electronic Engineering from Kwangwoon University.
He made his debut in 2015 as a member of ULALA PRAISE with their 1st full-length album "Sunny Day" (써니 데이). In 2016, ULALA SESSION went through several lineup changes and he was added to the band and actively performed with them until he decided to leave in 2019. He is currently active as a soloist.
(Source: MyDramaList)