This study proposes a gamification method which promotes the Pro-Environmental Behaviors (PEBs) on the target of young men. It utilizes game user's favor to the virtual agent, and it promotes user's reports of actual PEBs. In this paper, the game based on the proposed gami_cation were developed and a trial use was conducted with 25 participants for 28 days. As the result, although 11 participants answered "they hold a favor to the virtual agent", it was not clear that "intention to be honest" improved reporting actual PEBs to the virtual agent. Therefore, a psychological model was constructed and analyzed by a covariance structure analysis. As the result, it was found that "felt favor" and "felt to be honest" to virtual agent decreased the desire of false reporting in the game.