NGT48 official web site announces their members Tano Ayaka and Yamaguchi Maho will not participate in NGT48 3rd Anniversary and Niigata Port Opening 150th Anniversary Event, which will be held at Bandaijima multipurpose plaza on 12 January 2019.
Note: According to NGT48 official announcement (on 10 December 2018), Kashiwagi Yuki will not participate in the event because of a scheduling conflict.
Original source: NGT48 official site