Cut the fried tofu in half.
Roll the fried tofu gently with chopsticks to make it easier to open into a bag.
Place the fried tofu in boiling water to remove excess oil.
Remove the tofu from the water, drain in a strainer, and pour cold water over it to cool.
Squeeze the tofu by hand to remove as much water as possible, ensuring it can soak up the marinade.
In a bowl, mix water, mirin, soy sauce, and sugar until well combined.
Arrange the fried tofu in a pot and pour the marinade over them.
Bring the pot to a boil, then cover with parchment paper and simmer on low heat for 10-12 minutes, occasionally spooning the sauce over the tofu to marinate evenly.
Turn off the heat and let the tofu cool.
In a bowl, mix vinegar, sugar, and salt to make sushi vinegar.
Pour the sushi vinegar over hot rice and mix using a cutting motion with a rice scoop to evenly coat the rice.
Let the rice cool for a few minutes, then mix in the white sesame seeds.
Wet your hands with vinegar water to prevent the rice from sticking.
Form 10 sushi balls, each weighing about 35-40g, for easy placement into the fried tofu.
Drain the excess juice from the fried tofu, leaving a little to keep it moist.
Open the tofu and prepare to fill with rice.
Insert the rice into the tofu, ensuring it reaches the corners. Fold the top skin over to close.
Serve with pickled ginger on the side and enjoy.