Prepare sushi rice according to package directions. While warm, gently stir in rice vinegar to taste.
Choose ripe, firm pineapple. Wash, peel, and cut into long, thin strips. Pat dry with a paper towel to remove excess moisture.
Optional: Prepare filling. For sweet and creamy, mix pineapple with cream cheese. For savory, add cooked and chopped beef bacon. For spicy, add chili flakes or hot sauce.
Place a sheet of nori on a bamboo rolling mat. Spread a thin layer of sushi rice evenly, leaving an inch of space at the top.
Arrange pineapple and other fillings in a line across the center of the rice.
Lift the edge of the rolling mat and gently roll tightly, using the mat to help. Wet the top edge of the nori with water to seal.
Use a sharp knife to cut the sushi roll into 6-8 equal pieces, wiping the knife clean between cuts.
Arrange sushi pieces on a plate and serve immediately. Garnish as desired (sesame seeds, microgreens).