Yam Roll tells the story of an exotic land of sushi and how one of its inhabitants, a super-powered cab driver named Yam Roll, braves monsters and bad guys all in the name of unrequited love. Despite being well liked in Happy Kingdom due to his good nature and sweet, root-vegetable flavouring, Yam Roll is still a frustrated guy. Why? Because he is hopelessly in love with the town sweetheart, a spicy tuna roll named Minamiko.