Evoker is a narrative-based facial expression game. Due to the COVID-19 pandemic, adolescents should be wearing masks in their daily lives. However, wearing masks disturbs emotional interaction through facial expressions, which is a critical component in emotional development. Therefore, a negative impact on adolescent emotional development is predicted. To solve this problem, we design a narrative-based game Evoker that uses real-time facial expression recognition. In this game, players are asked to identify an emotion from narrative contexts in missions, and make a facial expression appropriate for the context to clear the challenges. Our game provides an opportunity to practice reading emotional contexts and expressing appropriate emotions, which has a high potential for promoting emotional development of adolescents.