Cut Tofu into 1" thick squares. Cut Naganegi into 2" long pieces. Cut sliced beef into bite-size pieces.

In a frying pan, heat oil at medium heat, brown the Naganegi, and cook the beef slightly. Take out from the pan and set aside.

In a medium pot, cook Soy Sauce, Sake, sugar, and water together until boiling. Keep the sauce simmering, add Tofu, Naganegi and boiled eggs for a few minutes, then remove from the sauce. Add cooked beef to the same sauce and cook for a minute. Remove immediately so the meat doesn't get tough.

Cut eggs in half. Pack Steamed Rice in 3/4 of 2 Bento boxes, and fill the rest of the box with egg, Tofu, and Naganegi. Place beef over the rice. Garnish with Benishoga.