That's an interesting trade. If you entirely ignore the Bitcoin aspect of it, you're just investing claims against a bankrupt Japanese company which is being competently administered in the ordinary course of a 民事再生。 Currently 100 yen worth of claims looks like it will receive 25 yen worth of satisfaction at a non-deterministic time between one and two years from now. But, but, but: something like 20 of those 25 yen are presently tied up in a non-liquid-but-very-volatile[+] security, so buying bankruptcy claims gets you effective 2:1 leverage on that security. (Handwavy assumptions: you're sure of getting the 5 yen back that is actually presently held in yen and you can borrow yen for approximately 0% in quantity, so essentially you're paying 10 yen for 20 yen worth of exposure to the security.)

[+] Yes, you can sell 1 BTC without meaningful price impact, but you can't sell 200k BTC without meaningful price impact, so it is not liquid by the standards of hedge funds.