On my walk today I came across a huge oak leaf…it was mostly green with red edges. This leaf would have been huge on a big tree. However, this really big oak leaf was clinging to a single twig that was growing from a dead wood pile. The twig is about a foot and a half high and literally a twig. I can't give you a dimension because I can't talk that small.
So the huge leaf is hanging there and I started thinking about what would happen to this leaf when it let go. It probably would fall directly under where it hung and eventually turn into soil. I went out this afternoon to take some pictures of the leaf for my blog and it was still hanging there. I wonder if leaves let go easily or do they have to have their grips pried off like I do sometimes.
I know you were using the oak leaf as a metaphor for uke, but I couldn't resist throwing in a horticultural "fun fact," since it's what I do for a living. Oaks originally were a Southern tree, their range expanding into New England only after the climate started warming following the end of the last ice age 10,000 or 12,000 years ago. Northern deciduous trees, such as sugar maples and birches, have been here longer and are adapted to the drying, frigid weather of northern winters. They get rid of their leaves in order to conserve water during winter, since their leaves would lose vast amounts of water through their surface areas. They do this by creating abscisic acid and ethylene, which form a rubbery plug between the leaf's petiole -- stem -- and the twig it's attached to, thus cutting off the water supply and letting the petiole dry up and disconnect from the twig. Oaks do not fully have that ability.
So, oaks' petioles cling to the twigs until a strong-enough wind blows them off, or otherwise they hang around until spring, when the buds of the year's new growth push the old leaves off. That's why you'll often see oaks with clumps of dead, brown leaves still hanging on them in January.
Not sure how that would relate to uke's grip on nage, but I'll leave it to aikido folk to find a connection.