Japanese Virtual Boy V-Tetris Bullet-Proof Software Inc. sales promotion toy:
Although the true character of the object is a mystery (we refer to looking
at the photographs)
It seems that it is a structure in which a 1.5v LR-41 battery is inserted, which makes it emit light as
far as I understand, look at the backside photograph and see how it seemingly is
a shining toy that can give light. Quite possibly it works much like a
twist&turn cube in the sense that you can change it's shape like a puzzle
while trying to make Tetris blocks.
Original price: ¥500
Releasedate: 30 September 1995
Ad & Manual of how the toy works:

Front:

Back:
