Originally a four-member group, MASC debuted on August 19, 2016, with the mini album Strange. On October 17, 2020, the group announced their disbandment four years after their debut.

On May 3, 2023, following MASC's appearance with two members on JTBC's Peak Time, they signed an exclusive contract with PCS Entertainment, therefore reforming the group as a duo. On May 9, the group changed their official name to SEVENUS.

On July 11, 2023, the duo took to social media to announce their first single album titled Summús! Now, on July 13, 2023, they took to social media to unveil the official tracklist for their first mini album, revealing 'Wonder Land' as the title track!