SF9 took the second place spot on the daily album chart of Oricon, Japan's largest music sales website, with the 3rd Japanese album 'GOLDEN ECHO' released on December 9th. Despite the situation where activities in Japan are impossible due to the aftermath of the new COVID19 pandemic,with it being meaningful as it is listed on the chart next to extremely popular Japanese singer Masaharu Fukuyama.

A total of 13 versions of this album have been released simultaneously, including the regular half, the first-time limited-time A•B, the FNC STORE limited-edition limited-edition special-picture class by member, and the first-time limited-edition A and B, the 2021 calendar.

SF9's new album “Golden Echo” means the best reverberation. It contains the wishes of the members that they want to continue to have a good influence on the public. A total of 10 songs including Japanese versions such as 'Summer Breeze', 'Good Guy' and 'RPM', which were released in Korea, are included, covering a wide variety of genres. In addition, the featured song “See U Tomorrow” was added to the speciality of Japanese celebrity IMALU and artist "LULU X" who participated in writing the Japanese lyrics.