Sonny Tuna loves being taken care of by his mama, but he has also longed for the kind of adventure that doesn’t require her to watch over his shoulder. When a sudden change in her work schedule forces her to leave Sonny home alone, he is thrilled for the chance to prove that he can be responsible. He goes about the day adding his own creative twist to every rule and tradition—surprising himself by how much fun responsibility on his own terms can be.

But bending Mama Shirley’s rules comes with a price that Sonny is not sure he can pay on his own. He uses the experience and lessons he gathered along the way to make it through the day, only to find that he still has a lot to learn. Join the very first adventure of the Sonny Tuna series to see how he faces his greatest challenge yet: The Most Terrible Tummy Ache.