Melt butter in a medium saucepan over low heat and add marshmallows. Stir marshmallows until completely melted. Remove mixture from heat and add cereal. Stir to coat cereal evenly in melted marshmallows.
Roll out the fruit roll-ups. Place 1/4 of the coated cereal onto each fruit roll up and spread and gather toward 1 side of roll up. Place 2 licorice twists onto the center of the spread out cereal mix. Wrap and roll the candy and fruit, maneuvering the licorice to the center of the roll, so that the finished product resembles a sushi roll. Repeat with remaining rolls.
Place a sharp knife into a bowl of very warm water. Cut candy sushi with warm knife and arrange on a plate then serve.