I recall that HIS was criticized by foreigners because they refused to offer certain cheap return fares to non-Japanese clients.

I think HIS made that decision because they felt that their gaijin clients were costing them money by throwing away the return coupons of cheap return fares - and HIS was getting penalized by the airlines.

Bottom line - If you get a cheap fare from HIS and leave them to pay the penalty, there probably won't be any consequences for you. (And I won't feel particularly sorry for HIS).