Kowa released the Six system (Six, Six MM, and Super 66) to compete with Hasselblad, Bronica, and other manufacturers of 6x6 120 SLRs. Major improvements over the mount’s lifespan include multiple exposures and interchangeable film backs.

Unfortunately, finicky handling and reliability issues held the Kowa back and the system never saw widespread adoption. Despite this, if handled with care the Kowa system is capable of keeping pace with its competitors, including Hasselblads, in terms of image quality.