Risa Niigaki
ZYX-a disbanded in January 2011 alongside the other revival units, excluding High-King. In 2013, for Hello! Project's 15th anniversary, ZYX-a reunited with its remaining 4 members Momoko Tsugunaga, Maasa Sudo, Ayaka Wada and Chinami Tokunaga and featured former member Risa Niigaki as their special guest.