I watched an interesting video (don't have the link) on a japanese turner that shined a flashlight through the bowl sides. In some places the end grain was gone. He had techniques and tools that I've never seen and he sat down with the lathe, also on the floor. The tool met the bowl surface at least 6 inches from tool rest and at least 3 inches below. The tools look handcrafted, possibly made by the turner.
The are used as the base for those amazing lacquer bowls.
They strive for lightness and then add lacquer base coats and then lacquer final coats. And polish with a fine dry compound with bare hands. The turner only does turning. The base coat and final coats are applied by experts in that and the polishing is also done by separate experts. The polishers have to keep their hands soft and smooth.
These are very high end lacquer bowls. The bowls are desgined to be easily held one-handed for eating/drinking. Perfect for a noodle dish.