S.I.S (에스아이에스) was a four-member girl group under XX Entertainment.
They originally debuted with six members on August 25th, 2017 with the single album “I’ve Got A Feeling”.
They unofficially disbanded sometime around March 2021 when XX Entertainment deleted S.I.S’s Facebook & temporarily privated S.I.S’s Instagram.
Their name stood for “Serendipity In Stars”.