Koishi

Koishi (written: 小石 lit "small stone") is a Japanese surname. Notable people with the surname include:


 * Hirotaka Koishi (小石 博孝), Japanese baseball player
 * Kiyoshi Koishi (小石 清), Japanese photographer
 * Tatsuomi Koishi (小石 龍臣), Japanese footballer
 * Tetsuya Koishi (小石 哲也), Japanese footballer
 * Yūma Koishi (小石 祐馬), Japanese cyclist
 * Koishi Komeiji (古明地 こいし), a character from Subterranean Animism, the 11th Touhou game