1. Make rice buns In a medium bowl, add steamed rice, katakuriko, sesame and a dash of salt. Mix them well and set aside.
2. Divide the rice into 8 portions. (1 portion = about 90g), fill the circle mold with the seasoned rice. and gently shape the rice bun by pressing it down to flatten it. Repeat with all the rice until you have 8 buns.
3. In a skillet over medium-high heat, heat 2 tbsp vegetable oil, then reduce the heat to low and place the rice buns. Cook them and turn them over, until crispy. Transfer the rice buns onto the plate and set aside.
4. Make tsukune wrap the tofu with paper towel and micro-wave it (600W) for about 1 to 2 minutes. Break the drained tofu into small pieces.
5. In a medium bowl, add ground chicken, drained tofu and the rest of ingredients A. Mix it all together until everything is evenly combined.
6. Heat 2 tbsp oil in a skillet over medium heat until hot. Then shape the chicken into flat circle patties and place them in the skillet. Fry on both sides until lightly brown. Cover and simmer for about 4 to 5 mins or until cooked through. Transfer the tsukune patties to a plate. Set aside.
7. In the same skillet, add all the sauce ingredients and bring to a boil. Place the tsukune patties in the sauce. Simmer on a low heat until the sauce starts to thicken. Set aside.
8. Make scrambled egg Lightly whisk the eggs, salt, sugar and milk together until the mixture is homogeneous. Heat 1 tsp oil or butter in a small frying pan, when the pan is hot enough, pour in the eggs, stirring, until the eggs are fully cooked through. Set aside.
9. Assemble the burger Spread some mayonnaise on the rice buns (optional), then spread the teriyaki sauce as well. Top with lettuce leaves, place the tsukune on top of the lettuce. Put some scrambled eggs. Put about 1 tsp mayonnaise over the eggs. Place another rice bun on top of it.