The first secret super move to be introduced in an arcade vs fighting game was Ryuuko Rambu from Ryuuko no Ken (Art of Fighting). Since Art of Fighting was SNK's flagship game and the first title of the famous 100 mega shock series, it was decided to exploit the idea of the super move to push the image of the game to the maximum. SNK thought it well to advertise it widely by organizing a prize competition. Basically it was necessary to guess Ryuuko Rambu's execution by writing the solution directly to SNK. The first 10,000 winners would be awarded an exclusive deck of Ryuuko no Ken cards. The competition was announced in issue no. 78 of Gamest released on August 30, 1992, and the solution was always published in the same magazine on 11-30-1992.
Curiously, SNK of America copied the initiative a few months later, when the solution was already known to the Japanese public, calling a contest called MASTER THE MAGIC CONTEST, publishing it in Game Pro magazine and, probably, on other sources. The formula was the same, but America.... you know, it's richer. So the first prize was a brand new NEO GEO GOLD. Plus the smaller prizes for the next 1100 who would guess the answer.
The green advertising flyer indicates that in May 1993 the contest winners will be published on Game Pro.
There was a winner for the MASTER THE MAGIC CONTEST, actually there were 3 of them. The news was published in the July 1993 issue of Game Pro. From the article it seems that each of them won a Neo Geo Gold System. I can therefore deduce that out of the 1101 prizes up for grabs, only these three players discovered the super move.