In a large mixing bowl, combine cooked sushi rice, sesame oil, and Japanese Kewpie mayo. Stir gently to incorporate the flavors.

Fold in the drained canned tuna into the rice mixture, ensuring texture is kept intact.

Adjust the creaminess by adding mayo 1 tablespoon at a time if desired, mixing well.

Press the rice and tuna mixture down in the bowl to create a compact layer and cut into 8 equal portions.

Roll each portion gently into a ball, about the size of a ping pong ball.

Wrap each rice ball with a strip of seaweed, leaving a little exposed for presentation.

Serve the Tuna Mayo Rice Balls immediately or store them in an airtight container in the refrigerator.