Research on and the development of technology that promotes human subjective well-being is crucial for the current global information society. Focusing on positive psychological intervention in social communication through mobile devices, this study proposes an input method to promote subjective well-being by recommending positive words and phrases for their negative counterparts. Accordingly, a design workshop was conducted to develop a reframing dictionary in Japanese. This dictionary constitutes a collection of negative words and their corresponding positive words and phrases that convey the same meaning. We also developed an input method that encourages users to select positive words and phrases when they enter a negative word. Preliminary evaluation results indicate a significant difference in positive affect ratings before and after communicating on social networking sites using the proposed input method. Thus, this input method contributes to promoting psychological well-being during daily information activities.