To promote motivation and interaction among learners for relationship education in online learning, we designed a digital gamified learning activity for relationship education combined with conceptual and reflective scaffolding. We measured the learning achievement of learners' knowledge, motivation, anxiety and flow during the activity. This study used a quasi-experimental method and consisted of a control group (traditional distance learning), experimental group A (gamification with conceptual scaffolding), and experimental group B (gamification with conceptual scaffolding and reflective scaffolding), with a total of 80 participants. The results of the study indicated that learners using this gamification design had high flow and low anxiety, and were more motivated to learn than when using traditional distance learning. The results indicated that all three groups scored significantly higher on the posttest of learning achievement than on the pretest. The two experimental groups were significantly more motivated than the control group, which means that the distance gamified relationship education activity was more motivating than the general distance learning approach. This study also found that experimental group B may have engaged in more reflection and discussion due to the additional reflective scaffolding, as the approach facilitated the use of conceptual scaffolding and promoted learners' cognitive thinking and refinement of knowledge.