Cut eggplant vertically in half, and cut into 1/4" (6mm) thick half rounds. Soak in water for a few minutes, then strain. Peel and grate ginger root.
Heat oil in a frying pan at medium heat. Cook ground chicken until browned. Add strained eggplants, and cook for a couple of minutes. Add water, cover, and cook for another couple of minutes. Season with sugar, soy sauce, Mirin, and Sake. Stir and cook for a minute. Cover and keep it warm.
Cook Udon noodles, frozen or dried, according to the package. Strain water well.
Plate Udon, pour eggplant and chicken along with the sauce over the Udon. Top with sliced green onion and Shichimi chili pepper.
