Monday Kiz's Lee Jin Sung and SeeYa's Kim Yeon Ji have collaborated for a duet for the first time ever!

Lee Jin Sung and Kim Yeon Ji have released their duet song "Hurting but Happy". Can Entertainment stated, "This is the first time the two vocalists have met since both of their debuts. We are trying to show the different charms the two vocalists have with this new song."

They continued, "They worked really well together, as if they had been collaborating like this for a long time. They were also good at expressing the lyrics and emotions of the song in detail."

In related news Lee Jin Sung has been busily preparing for Monday Kiz's comeback while Kim Yeon Ji has been preparing for her solo activities.