Rinse the sushi rice under cold water until the water runs clear.
Combine the rinsed rice and 1 1/4 cups water in a medium saucepan. Bring to a boil over medium-high heat.
Once boiling, reduce heat to low, cover, and simmer for 15 minutes until water is absorbed and rice is tender.
Remove from heat and let rice sit, covered, for 10 minutes.
In a small bowl, mix rice vinegar, sugar, and salt until dissolved.
Transfer cooked rice to a large bowl and gently fold in the vinegar mixture. Allow rice to cool to room temperature.
In a medium bowl, combine diced tuna, soy sauce, sesame oil, honey, green onion, and grated ginger. Stir gently to coat and set aside.
In a separate small bowl, whisk together mayonnaise, Sriracha sauce, lime juice, garlic powder, and sugar until smooth to make the spicy mayo.
Divide the sushi rice evenly between two bowls.
Top each bowl with the marinated tuna, diced cucumber, diced avocado, and shredded carrots.
Drizzle the spicy mayo over the top of each bowl.
Sprinkle toasted sesame seeds over each bowl for garnish.
Serve immediately and enjoy your fresh tuna poke bowl with spicy mayo.