Shy, reclusive quintuplet Lumi has never left her bedroom—until her failing grades force her four sisters to hire the school's top student, Apollo, as her tutor. On the surface, Apollo is confident and socially effortless, but beneath the charm lies a young man who struggles to understand emotions beyond the surface level, copying others' personalities just to feel normal. As Lumi slowly emerges from her shell through late-night gaming sessions and study dates, she discovers the real Apollo hiding behind his masks—and falls for him. Now, with her four meddling sisters cheering her on, the girl who's weary of everything must find the courage to confess to the boy who's never truly understood anyone... until her.