I never knew that kiwi fruit had family in Japan, but apparently they do! Our neighbour brought these around for us yesterday morning, they're called saru-nashi (monkey pear) ...and they have another name but I forgot it already...! They grow wild in the mountains, and I guess they're seasonal because I've never seen them before. Very yummy, a new favourite, they taste like a cross between kiwi fruit and fejoya. Highly recommended!
PS I just had a bit of a look around for more information, the Japanese name I'd forgotten was Kokuwa, and it's botanical name is Actinidia arguta. There's some more information on this site.