In a mixing bowl, whisk together soy sauce, sesame oil, sriracha, and rice vinegar. Combine mayo and sriracha.
Gently fold the diced tuna into the spicy marinade and refrigerate for 15-30 minutes.
Place a base of cooked rice in a bowl.
Spoon the marinated tuna over the rice.
Arrange the avocado, green onions, and other desired toppings around the tuna.
Drizzle with home-made Spicy Mayo.
Sprinkle with toasted sesame seeds.
Serve immediately and enjoy!