I was walking along today with my daughter and discoveried this. I asked around and no one seem to know what it is so I thought to give this forum a try. It is a vine/ climber, alternate compond leaf in group of three, ovate untooth margin. Fruits are berries in group of 3. Redish colour, short sausage shape, skin is leathery, inside is slimy with lots of seeds which are black. Flesh is griddy and slimy.
Akebia quinata. Those fruits should get dark purple when they're ripe. They are supposed to be edible, but I haven't had any interest to try them. There is a bit about them on Wikipedia: Akebia quinata - Wikipedia, but lots of other articles are on the net. Those leaves are supposed to be in groups of five! Maybe this is some relative.