Governess Nazuna-san  

Kateikyoushi Nazuna-san, 家庭教師〈ガヴァネス〉なずなさん

The Koyomi family used to govern Japan's underbelly. Now, only the young heir, Kashitarou Koyomi, remains. He must navigate his loneliness and resentment from others as he starts anew in isolation. Suddenly, a self-proclaimed caretaker and tutor emerges, introducing herself as "Nazuna." She declares her intention to transform Kashitarou into a powerful evil lord.