Nippon Computer Systems. Founded in 1980.
Used the brand "Masaiya" for game production and developpment.
In 2014, the company Extreme licensed the rights to the Masaiya brand games, for ports to mobile phones. Later the same year, all rights for all Masaiya-associated games were definitely sold to Extreme.
(Details from Japanese wikipedia on NCS: http://ja.wikipedia.org/wiki/日本コンピュータシステム)