Lala, the daughter of a nobleman, is sent to the castle of Walter the Feudal Lord, in place of her sister who has eloped. Lala is prepared to be treated harshly, but for some reason, Walter grows fiercely attached to Lala as though he was never even remotely engaged to her sister to begin with. ...... It's a story about a love fantasy of a yandere in a fantasy world!

貴族令嬢であるララは駆け落ちした姉の身代わりに、領主・ワルターの城へ行くことになってしまう。手酷く扱われることを覚悟していたララだったが、ワルターは何故か姉との婚約など最初から無かったようにララに激しく執着してきて……。異世界ヤンデレラブファンタジー！