Mobile instant messaging (MIM) services have entirely changed the communication landscape from where it was a decade ago. They have taken communication among humans to the next level. However, despite their massive popularity among masses, we do not know of specific reasons that drive continuous use of MIM apps (e.g., LINE, WhatsApp, and Snapchat). The current study bridges this gap by investigating the continuation behavior in the context of a popular MIM app called LINE. The study developed a comprehensive framework using three popular consumer behavior theories, namely theory of planned behavior, flow experience theory, and consumption value theory. A total of 309 middle and late adolescent LINE users participated in an online survey. The analysis revealed that perceived ease of use (PEOU), functional value, and social value exert significant positive influences on users’ continuation intentions. The PEOU was found to have the strongest influence among all. Additionally, social influence was found to have the significant but negative influence on users’ continuation intentions. However, other factors (perceived enjoyment, concentration, telepresence, and perceived behavioral control) have no role in predicting continuation intentions. Furthermore, continuation intentions were found to have no impact on users’ actual LINE use related behavior. The findings of the present research offer several theoretical and managerial implications.