A new approach to moral education using blended learning has been developed. This approach involves 10 scenarios that are designed as a web-based game and serves as a basis for group moral-consequence-based reasoning, which is developed based on a hypothetical-deductive model. The aim of the study was to examine the changes in students' blended learning interest and reasoning ability in a time series experimental design. After playing the game with the 10 initial scenarios during the first week of the study, participants were subjected to five blended learning sessions that required them to discuss the consequences of one of the 10 scenarios using hypothetical-deductive reasoning. After six weeks, the data from the 110 participants were analyzed using time series statistics. The results indicated that players were highly interested in the game, although their interest had a tendency to decrease slightly over time. Repetitive game play (i.e. practice) was positively associated with the players' moral reasoning performance. The study results may lend support to the design of a game with additional or more highly complex content for players to further develop students' consequential reasoning ability.