MAMAMOO previously confirmed that they would be releasing a best-of album this month.

After the confirmation of the release of the best-of album, MAMAMOO released a teaser image along with the date for the album release. On September 4 at midnight, MAMAMOO dropped the schedule plan. Starting September 5, the girl group will be releasing concept photos and other various teasers every day until September 15.

The upcoming compilation album is the girl group's first release since their 11th mini-album 'WAW' released this past June, as well as their first since Whee In decided not to renew her contract with RBW.

'I SAY MAMAMOO: THE BEST' will be released on September 15 at 6 PM KST, so don't miss out on any of the teasers that are coming!