Cut the tofu into bite-sized pieces and boil in a pot for about 1 minute.

Drain the tofu in a colander.

Toast the tempura flakes in a dry skillet (no oil) until lightly crisped.

Add the drained tofu to the skillet, gently mix, then add the mentsuyu and sugar. Bring to a simmer.

Pour in the beaten eggs. Cook until the eggs are just set but still soft. Serve over bowls of rice and top with green onions if desired.