These three seem to be new characters from the "Chamber of Time" game. Left to right: Balsa McVinegar, Lin-lin, and Zizi Delevingne.

The Romanized names come from this article: http://www.siliconera.com/2018/03/20/little-witch-academia-chamber-times-version-1-03-update-adds-online-offline-co-op/