Step 1
Rinse rice with cool water until the water runs clear; drain. Bring rice and 3/4 cup water to a boil in a pot. Reduce heat and let simmer until water is absorbed about 15 minutes. Let cool 10 to 20 minutes.
Step 2
Cut the sheet of nori into two 1-inch strips; reserve the remainder of the sheet for making tamagoyaki.
Step 3
Wet your hands and form the cooled rice into 4 equal portions. Keep your hands wet to keep rice from sticking. Create an indention in one of the rice portions using your thumb. Fill the indention with 1 teaspoon bonito flakes. Top with another rice portion to close the onigiri. Form into an oval shape and wrap the middle with a strip of nori. Make another onigiri with the remaining ingredients. Sprinkle white and black sesame seeds on top. Place in a bento box.
Step 4
Whisk together the eggs mirin and 1/8 teaspoon tamari together in a bowl; divide into 3 portions. Cut remaining portion of nori sheet into four 1/2-inch strips.
Step 5
Heat oil in a small saucepan or square tamagoyaki pan over medium-high heat. Add 1/3 of the egg mixture and cook until almost firm 2 to 3 minutes; if omelette is too firm it won't stick together very well. Slide onto a plate. Add the 4 strips of nori to the pan with some space between each.
Step 6
Cook another 1/3 of the omelette the same way but roll it up carefully in the saucepan with the nori. Slide the rolled-up omelette onto the edge of the first omelette. Cook the third omelette and roll it up sliding it on top of the second omelette. Let cool enough to touch about 5 minutes.
Step 7
Roll the entire layered omelette together with nori inside. Cut into 4 pieces. Place into the bento box alongside the onigiri.
Step 8
Mix 2 tablespoons tamari ginger and wasabi paste together in a bowl. Put the mixture into a portable container then put inside the bento box. Add the steamed broccoli and edamame.