This paper examines interactional processes through which personal difficulties or problems as experienced are defined and through which claims are made. First, I look into the constructionist idea of “claims. ” Then, the interaction between claimants is viewed as a reality-definition contest. I examine and develop the description of reality-definition contests formerly given by Loseke (1987). With an illustration of a case of claims-making regarding “fufu-bessei” (an argument against changing a married woman's surname to that of her husband), I discuss and show how one's experience and definitions of problems are involved and invalidated in the mechanism of reality-definition contests.