Tears well up in 88-year-old Izue Hamada's eyes as she holds up a halved nari (cycad) nut for me to see.

"Nari nuts are treasures!" she says. "If not for nari, we islanders would have died during the war."

Nari nuts are the staple crop of Amami Oshima, an island located between Kyushu and Okinawa. Historically, nari nuts were used in the production of local miso, but recently this cottage industry has become a commercial enterprise, resulting in miso that contains less of the nuts and more additives.