It's been announced that NGT48 will end their current team system and restart their activities. 

Currently, NGT48 is comprised of Team NIII, Team G, and Research Students. From now on, they will be active as "First Generation Students" and "Research Students." As such, Team NIII's last 'Hokori no Oka' performance and Team G's last 'Sakaagari' performance will be held on April 21 at NGT48 Theater. 

In December, Team G vice captain Yamaguchi Maho was attacked by two men in front of her home. As this started a riot, all performances scheduled at NGT48 Theater after January 22 was cancelled.

Source: natalie