Sai 【斎】5 The Japanese surnames etymology dictionary.
Toyama-ken Toyama-shi . Toyama-ken Toyama-shi Origin of Kusamajima (Kusajima). A place name with a record since the Edo period. Ishikawa-ken Nanao-shi In Shinmeicho Ishikawa-ken Hakui-shi Mr. Shibahara who was in Kamakura period in Shibagaki-machi told that he resides in Toyama-ken Toyama-shi Kusushima during the Warring States period and renamed it with Kusashima's "grass" . 芝原 reference.