Cook and season the rice. Add rinsed rice and water to a pot or rice cooker. Cook until tender. In a small bowl, dissolve sugar and salt in rice vinegar. Fold the vinegar mix into the hot rice and let it cool slightly—warm, not steaming.
Prep the crunchy topping. Toss shrimp with cornstarch, salt, and pepper. Dip in beaten egg, then coat with panko. Pan-fry in oil over medium heat 2–3 minutes per side until golden, or air-fry at 390°F (200°C) for 7–9 minutes, shaking halfway.
Toast extra panko (optional but elite). In a dry pan, toast 1–2 tbsp panko until golden for a final scatter of crunch.
Mix the sauces. Stir mayo and sriracha to make spicy mayo. In another small bowl, combine eel sauce (or teriyaki), a few drops of sesame oil, and a splash of soy.
Chop and slice. Slice cucumber, avocado, green onion; crumble nori; chop pickled ginger. Keep everything bite-sized for great fork action.
Build the bowl. Add a bed of seasoned rice. Layer on cucumber and avocado. Top with crispy shrimp. Drizzle spicy mayo and eel sauce. Finish with nori, sesame seeds, furikake, green onions, and a squeeze of lime.
Taste and tweak. Need more heat? More tang? Adjust with sriracha, soy, or vinegar. You're the CEO of your bowl.