Boarding School Juliet unfolds at Dahlia Academy, where students from the Eastern Nation of Touwa and the Principality of West live together despite a feud that has lasted for generations. Within the school, the "Black Doggies" and the "White Cats" keep that rivalry alive, and their respective dorm leaders, Romio Inuzuka and Juliet Persia, are expected to stand on opposite sides.
What no one around them realizes is that Romio and Juliet are already in love. Every day at the academy forces them to balance their feelings against the pressure of their dorms, their comrades, and the fragile peace that keeps the school from turning into open conflict. Their secret relationship makes even ordinary moments complicated, because being a couple in private while pretending to be enemies in public leaves them with constant risks, missed chances, and mounting tension.
As their bond grows stronger, the two are pushed to decide whether hiding forever is really possible, or whether their love can survive only if they are willing to challenge the feud that divides Dahlia Academy and the world beyond it.