The instructions are in Japanese but the accompanying diagrams are pretty clear on what must be done. Frederic did a bit of the translation for me - the solution requires 22 moves.
Only four pieces, but a unique and interesting idea for a sliding block design, and challenging too!
There appears to be very little information about Minoru Abe, the man himself. But check out Holt Davey's FaceBook page here about Abe.