The Extra Knights Japan version figures were made by Bandai in 1997. There are 7 different figures; Cloud, Aerith/Aeris, Barret, Red XIII, Tifa, Vincent and Sephiroth.  As far as I know, the first 5 figures were released first, and the other 2 some time after. Note that there are fake versions of the first 5 figures out there, for more information view the “Fakes” section.

There are also “first editions”, which are said to be more rare and valuable than the later ones. The first edition figures can be told from the later edition figures only by some small differences in the details of the figures. For example, the first edition version of Cloud has light yellow hair as compared to the brownish yellow hair of the more common version, and the first edition Aerith has red lips instead of pink.

The Extra Knights Japan figures are one of the most popular and sought-after FFVII collectibles. They are fairly rare, especially the sealed ones, but there is usually at least some supply. However, because of the high demand, the prices can be pretty high.