Rosetta is a grouchy old woman who owns a pizzeria in Colart. She hurts her back while trying to carry some groceries, and the Searchers insist on helping her. Golem wants to help her get her business back on track, since her staff has all quit because of her cantankerous attitude, but she refuses to let him know her ingredients. As time grows closer to the city bake-off, however, she realizes that she has no hope of winning and defending her title if she doesn't accept his help. She tells him about her Golden Mushroom ingredient, but while they are asleep that night the mushrooms get stolen. Undeterred, the two beat the odds and enter the bake-off, and Rosetta learns that new doesn't always have to be bad.
Rosetta's storyline contains similar elements to that of Mauro in Monster Rancher 4.