077p - 1996 Bandai Pokemon Box 3 Waterside and Town Pokemon (?)
ポケモンボックス3 水辺と町のポケモン
I am not sure about this, but hopefully this is helpful in narrowing down possible answers.
This figure matches closely in mold with the 1996 Bandai Pokemon Box 3 Waterside and Town Pokemon (ポケモンボックス3 水辺と町のポケモン) figure collection.
However, those figures are blue, while your figures are clear. This may be due to fading in color due to the sun or otherwise exposure.
There are more pictures of figures online that match your Staryu/Starmie figure, but also blue, albeit lighter:
Additionally, there is this picture of many figures in varying states of blue, which look like they are fading in color. This picture includes a clear Starmie, as well as a clear Moltres, Porygon, and Oddish (all of which are in the same set):
These figures seem to be largely from the set noted above (1996 Bandai Pokemon Box 3 Waterside and Town Pokemon) as well as 1996 Bandai Pokemon Box 4 Sky and Ocean Pokemon (which is also blue).
The lighter blue ones seem to be from pictures of loose figures, while darker blue ones are found in sealed boxes, which supports the sun-faded theory.
It is possible that your Starmie and Staryu figure is simply very sun-faded, to the point where it is now clear. However, I am not 100% sure that this same mold was not reused elsewhere to create a clear version.