Inside the box of goodies was akebi - I have no idea what it is in English. It's a Tohoku food apparently, Yamagata people are thought particularly savage, even from their fellow Tohoku-ites because they eat the bitter skin. According to kyoto foodie it's considered a fruit - the fleshy inside part is like a rambutan or lychee in taste but has fleshy seeds like a pomegranate (only much softer and fleshier). Also according to kyoto foodie the wild ones split open naturally whereas the cultivated ones need a bit of help from a knife. I guess these were wild ones.
Hiro's suggestion was cooking like miso eggplant, which I did. Very tasty. I cooked two - peeled one and left the other as is. I liked the skin on. Definitely not the food of a savage!