In case of the Taika Harigon, it was probably "too late, wrong mount".
In 1953 there was a Japanese lens maker ZUNOW which announced a 50/1.1 lens for the screw mount Leica - today a valuable collector's item
NIKON and CANON followed with f/1.1 and f/1.2 lenses. In 1961 there was the superfast CANON 50/0.95, the NIKON 50/1.1, Fuji and Konica 50/1.2 - all in Rangefinder mounts.
The fastest SLR lenses were the CARL ZEISS JENA Biotar (75/1.5) since 1948, ZEISS IKON Planar 55/1.4 1961 for the Contarex, and NIKKOR 58/1.4. Pentax and Minolta released their f/1.4 standard lenses as late as 1964.
SLR lenses were slower. Next, the optical developers had problems to create fast lenses with the well-known "standard" 50mm focal length - because of the longer back focus of SLR lenses compared to rangefinder. For that reason many fast SLR lenses were a bit longer (55 or 58mm) - which isn't bad after all, because 58mm is a very practicable "short telephoto" length...
The TAIKA HARIGON was by a margin the heaviest SLR standard lens but the fastest one. The company who made it was Taisei Kogaku Kogyo (Taisei Optical Industries) in Saitama (north of Tokyo) which later became TAMRON. So Taika wasn't a company, just a trade name for Taisei Kogaku.
Beside, there was a 58/1.2 for the ZUNOW SLR, but it is not known how many were build, when, or if it was earlier than the Harigon. It is even possible that it's the same lens whatsoever.
