Singer Kim Jung Hoon is back.

On July 3, Kim Jung Hoon released new mini album 5091 through online music stores, kicking off promotions. The album title "5091" signifies the number of days since Kim Jung Hoon's debut as boy duo UN.

Kim Jung Hoon, who has been active as an actor in Japan and China, now returned to Korea's eager fans awaiting his new album.

Four tracks are listed in the new mini album, including title song "Day."

Title song "Day" carries the sentiments of love under a cherry blossom tree. With a melodic piano sound, Kim Jung Hoon's soft voice sings of the memories of love.

Kim Jung Hoon stated: "The title song, 'Day.' carries a pretty melody, but is in fact a sad song. I think anyone who has parted with a loved one can agree and relate to the lyrics. The new album carries a lot of my worldview and color; I love songs that contain purity."

In the album, composer Kim Sung Wook participated in the making of the songs. Kim Sung Wook appeared on JTBC's "Hidden Singer" as Yoon Min Soo's voice soundalike, shocking even Yoon Min Soo himself.

Meanwhile, Kim Jung Hoon will kick off promotions with his release.