Place tofu between two plates. Place a heavy book on top and let sit until tofu has drained, about 1 hour, pouring out expelled liquid every 20 minutes.

Whisk together soy sauce, mirin, rice vinegar, and sesame oil in a small bowl.

Heat vegetable oil in a small pan over medium heat. Add garlic and ginger; gently stir and cook until lightly golden, 1 to 2 minutes. Stir into soy sauce mixture.

Cut pressed tofu into bite-sized pieces, then place into a bowl with tomato, onion, and cilantro. Pour in dressing and toss to coat. Garnish with sesame seeds.