Place cooked rice in a small bowl and mix with 1 ½ tablespoon of sushi vinegar using a wooden spoon. Separate into 8 small portions and make small balls.
In a small pot, boil shrimp with hot water. Once shrimp is cooked and pink, drain, and soak them in 2 teaspoon of sushi vinegar. Once cooled down, remove the tail and slice in half.
In the meantime, beat 1 egg. In a small pan, cook a very thin egg crepe using a bit of cooking oil. Remove from the pan and slice into thin strips.
On a plastic wrap, place 2 pieces of sliced shrimp, pink side down.
Place one of the rice balls onto the shrimp slices, and hold it firmly using the plastic wrap to make sushi ball.
Next, place two thin strips of egg on the plastic wrap making a cross shape. Place one rice ball and hold it firmly to make sushi ball.
Place one slice of salmon on the plastic wrap. Repeat the same process to make sushi ball. Repeat the same for tuna.
Place each kind of sushi ball into the bento box and garnish shrimp sushi ball with a bit of mayonnaise.
Boil water in a small pot with a pinch of salt. Put spinach and boil for 2-3minutes. Drain and squeeze to remove excessive water.
Mix ground sesame, sugar, mirin and soy sauce in a small container. Mix with spinach.
Place them next to the sushi balls inside of the bento box.
Peel carrots and cut into very thin julienne.
Pour sesame oil on a pan and cook the carrot for two minutes over medium heat.
Add seasoning and continue cooking for 3 to 4 minutes until done.
Place carrot kinpira inside of a bento box and sprinkle sesame seeds.
Cook chopped onions in a pan and cool them down.
Salt and pepper the ground chicken in a bowl and mix well.
In the bowl, add breadcrumbs, egg, and chopped onions and mix well with chicken.
Make 12 chicken balls and flatten them by pressing down with a palm of your hand.
Heat frying pan and cook chicken balls with cooking oil. Cook both sides until lightly browned.
Mix teriyaki seasoning in a small bowl and add it to the pan. Cook until the liquid is gone.
Place one or two chicken balls into the bento box.