AKMU, which has been at the top of the music charts for eight days, sincerely solved their musical concerns and growth through "SAILING Diary."

YG Entertainment unveiled the first installment of AKMU's album-maker video "SAILING Diary" on its official blog at 10 a.m. on October 2.

The video clip features AKMU's story about the new album, with Lee Chan-hyuk and Lee Soo-Hyun being cross-edited, respectively. While Lee Chan-hyuk was working on his creation, Lee was honest about his feelings in the process of expressing his new music.

When asked, 'Is this song from experience?' Lee said, "Yes. There is no fiction this time," he replied sincerely.

"It seems that understanding of the song and access to it has become difficult," Lee said. "It's a little hard for me as a younger brother to carry on his emotions, and I don't know the details," he said. "What was surprising was that I knew my brother's story so well but I didn't know how to empathize with him."

"I've never felt so much agitated while singing," Lee said. "There are a lot of songs that I feel like I'm going to cry from the beginning to the end."

Lee also expressed surprise at his musical sensibility, saying that until LAST GOODBYE, "You knew what true love is." In the title track, the depth has changed to the point where he feels "like an old man."