Lena Reena Rene Risheranto, the first princess in line to the throne of the Principality of Rivetaria, attends school as an exchange student in Hyuuga Nobuyuki's class. With her elegant blond hair, piercing blue eyes, and youthful appearance contrasting with her mature figure, Lena embodies the epitome of a princess. However, her occasional moments of vulnerability lead to a titillating and comedic romance filled with unexpected twists and turns.