Etymology and distribution of 施井.

Shii 【施井】^{レベル1
Very rare}  The Japanese surnames etymology dictionary.

Aichi-ken , Shiga-ken , Toukyou-to .

① Shiga-ken Moriyama-shi Originated in Sugiee town. A place name with a record since the Edo period. The place name also pronounced Suga.

② Abstract . Sugimoto's abbreviation. Tochigi-ken Ootawara-shi Shiroyama was in the Edo period in the clan Otahara of the clan government office. The same clan says that he changed the name, leaving "Sugi" of Sugimoto surname. 杉本 Sugimoto reference.