Matsui Naoko (* April 4, 1961) is a prolific Japanese voice actress (seiyuu) from Hakodate. Matsui was a member of Production Baobab for 20 years before becoming a freelancer and joining Up and Ups in January 2013. She is also a voice acting instructor. Matsui is most notable for the roles of Uru Chie in High School! Kimengumi, Katsumi Liqueur in Silent Mobius, Chiyoko Wato in Mitsume ga Tooru, Run Run in Mahoujin Guru Guru, Roux Louka in Mobile Suit Gundam ZZ and Suzuki Sonoko in Case Closed.