To explore different functions of gratitude and indebtedness, two questionnaire studies were conducted with female university students in Japan. These studies examined the correlations between positive feelings, regret, and indebtedness when receiving a favor, and the resulting feelings such as the enhancement of prosocial motivation (wish to help) and the obligation to help others. The results of Study 1 suggested that positive feelings and indebtedness in a hypothetical helping situation differently correlated with other variables: Positive feelings had a significant positive correlation with the enhancement of prosocial motivation. In contrast, indebtedness had a significant positive correlation with enhancement of obligation (should help). Study 2 was conducted by using positive and socially conceptualized feeling items such as the fulfillment of friendship. Results suggested that the social conceptualization might add obligatory nature to the positive feelings.