Cook rice: Fill a medium saucepan with salted water and bring to a boil. Add rice to boiling water. Cook, uncovered (like pasta), over high heat, stirring occasionally, until tender, 20–25 minutes. Drain rice well, return to pot, and cover to keep warm.

Pickle veggies: Trim ends from radishes, then halve or quarter (depending on size) and thinly slice. Trim ends from cucumber, halve lengthwise, then thinly slice into half-moons (peel if desired). In a medium bowl, whisk to combine rice vinegar, 1 tablespoon water, 1 teaspoon salt, and 2 teaspoons sugar. Add radishes and cucumbers and toss to coat. Set aside to marinate.

Make sauce: In a small bowl, stir to combine mayonnaise, all of the Sriracha, and 2 teaspoons of the furikake (save rest for step 6).

Prep shrimp: Pat shrimp dry, then cut each one into thirds. Season all over with salt and pepper.

Cook shrimp: Heat 1 tablespoon oil in a medium skillet over medium-high. Add shrimp and cook, stirring, until opaque and cooked through, 2–3 minutes. Remove skillet from heat and stir in half the sauce.

Finish & serve: Using a slotted spoon, drain pickled veggies and add pickling liquid to rice and stir to combine. Season to taste with salt. Spoon rice into bowls then top with shrimp, pickled veggies, and drizzle with remaining sauce and sprinkle with remaining furikake.