Depending on what you are trying to do there IS an adapter for about $25 to convert the proprietary Kubota to a standard spline. Problem is there is no way to lock it onto the PTO stub on the tractor. May work for you anyway depending on what you are doing, I didn't trust it to not come off. It is made by Hub City.
Also you can't use just the Kubota yoke because the cross is a weird metric size that doesn't match up to any tractor yokes.
Also you can't use just the Kubota yoke because the cross is a weird metric size that doesn't match up to any tractor yokes.