That was my first thought but, crucially, the bankruptcy administrator is not holding a pile of yen. If he were merely holding a pile of yen, this is a pretty boring deal, and you'd be right -- it's a straightforward swap of liquid cash for illiquid cash with an embedded premium for legal risk.

But the bankrupt entity holds 200k odd Bitcoins, and that changes things a lot. I wouldn't make this trade even at an 85% discount to face value, because I think there's a significant likelihood that BTC goes to zero, and so would not buy it and especially would not buy it with embedded leverage.