Hello! Welcome to the Helpful Gardener Forum. I'm Applestar

ElizabethB is being too kind.
We seem to be having technical difficulties with the uploaded image.
I tried looking up for any tomato variety called "kaya" but only results I came across were references to Indian curry dish that has something to do with green beans....
Are you saying the fruits are size of cherry tomatoes, still green, but one fell off as though ripe?
There ARE green-when-ripe varieties of tomatoes. Some turn amber-colored at blossom-end/bottom as they ripen, and some remain green. But there IS a way to tell when they are ripe -- the surface of the fruit changes from shiny hard green to satiny green and will "give" a little when pressed, just like ripe fruit -- mango for example. No matter what the color, satiny texture and a slight give are my favorite indicators to determine ripeness. I usually pick them at this stage to finish ripening -- 2-5 days in the house.