It Does Exist!
There's one topic that on and off being discussed by Seiko enthusiasts in different forums and interest groups. Seiko 5 Quartz, did Seiko ever produced such a watch or series.
Will go into detail about the mystery of Seiko 5 Quartz later on, but for now, a brief description of this myth can be summarized into a few sentences. Seiko 5, when introduced in mid '60s, were talking about 5 major rules to put in this 'FIVE' series. One of the rules is, the caliber has to be an automatic. However, over the time in the first half of the '80s, Seiko had released a limited run on quartz powered watches with the signature of Seiko 5. Some enthusiasts and collectors didn't think these are made by Seiko but fakes. But some, claimed that these are real. Some of these samples were acquired, and had been carefully examined by these peoples. Unlike the typical fake Seiko, from a lot of details, these examples were mostly believed to be legit.
And the most solid proof was, one of my friends who had actually asked Seiko by mail and asked if these watches were made by Seiko. And their official reply by mail was, yes, they did made some.
So, here's one of those, manufactured by the Daini factory, a quartz five, in 1980. I also have another quartz 5, made in the mid '80s, however, it is from the other factory of Seiko, Suwa. I will show that later as well.
Very interesting and controversial piece of Seiko timepiece, which I think I found the answer, by having two of them physically in front of me.