In Mystic Messenger, you play a female protagonist with no fixed name — often called simply MC or the heroine. After downloading a mysterious app, MC is led into living in a secured, locked apartment owned by someone named Rika, the founder of a charity organization called the RFA (Rika's Fundraising Association). There she meets the six remaining RFA members and is given the task of organizing the group's long-awaited third party by inviting guests. Along the way she can pursue one of five available love interests — each with their own route and backstory — while gradually uncovering the truth behind the RFA.