I can't become your hero.

Adrian, the young heir of Count Zeals, visits his fiancée, Zasha, the daughter of Viscount Rodolia, whom he hasn't seen in a long time. However, the one who appears is her half-sister—and when Zasha appears in a drastically changed form, even hinting at a replacement of her fiancé, Adrian consults with his father, Count Zeals, with a certain resolve.