The Cruel King I'm Marrying as a Substitute Bride is My First Love?!
Migawari de Totsuida Reikoku Kokuou wa Hatsukoi Aite deshita / 身代わりで嫁いだ冷酷国王は初恋相手でした / The Tyrant King She Married in Place of the Duke's Daughter Turned out to Be Her First Love / The Tyrant King She Married in Place of the Duke’s Daughter Turned Out to Be Her First Love~

Kanae Yano, a 28-year-old single woman with no boyfriend, is suddenly summoned to another world. There she meets Rita Scryne, a duke’s daughter who looks just like her, and Rita’s father, Zack, who ask Kanae to take Rita’s place in an arranged marriage to the feared King Eugene Astaroth, known as the “Merciless Wolf.” The magic that brought Kanae to this world cannot send her back, leaving her little choice but to accept. But when she meets the king, she discovers that Eugene is her first love. Their reunion begins a fantasy romance in a world neither of them expected.