Neoca was a Japanese company that made the Mizuho Six 6×6 folders from 1951, and later Neoca cameras.

The company's full name at first was Mizuho Kōki Seisakusho (ミヅホ光機製作所), this name was translated as Mizuho Optical on some body engravings, and the logo was MKS in a stylized lens scheme. In July 1952 the company became Mizuho Kamera Kōgyō K.K. (ミヅホカメラ工業㈱), translated as Mizuho Camera Ind. Co, Ltd (observed on a box for a Mizuho Six, for sale in an online auction). While Mizuho seems to have consistently been written in advertisements as ミヅホ (never ミズホ), the company is, rightly or wrongly, sometimes referred to as 瑞穂 (which too would be read "Mizuho").

In November 1954 the company became Neoca, more fully Neoca Kabushiki Kaisha (ネオカ株式会社).

Neoca went bankrupt in January 1960.