Place the beans in a mortar and crush them roughly with a pestle, adding the sugar and the pinch of salt a little at a time. Place the bean mixture in a clean pot and cook over low heat, stirring constantly, for 5 to 10minutes. The mixture will thicken slightly. Pour into a clean bowl and let cool to room temperature.
Wash and drain the rice. Add the water and salt and cook in an electric rice cooker. (The aim is to make slightly firmer rice, which is why less water than usual is used.) When the rice is cooked, let it rest for up to10 minutes. Sprinkle the salt on top, then semi-mash the rice using a mortarand pestle or a small wooden spoon. Divide into 14 to 16 portions and mold intoballs.
To assemble the ohagi, first wet your hands with salted water. Shape the still-warm rice balls into ovals, cylinders or rounds. (The shape and size of ohagi, by the way, are up to you.) Cover each ball with a thin film ofchunky bean paste. Roll the balls in the sesame seeds or soybean flour mixture,covering them thoroughly, or leave them as is. You can also make a small holein the bottom of the rice balls, add a small core of red bean paste, and thenproceed with the above method for covering the ohagi. Serve within 12 hours,with plenty of hot green tea as accompaniment.
*If you prefer to use ready-made chunky and or smooth red bean paste called anko, that works too!