デスゲーム漫画の黒幕殺人鬼の妹に転生して失敗した (Series) favorite_border

[DeepL Translation - needs review] Volume 1 Introduction: Mai, who has a perfect brother-in-law, has dreamed of marrying her brother since she was a little girl, saying "I'm definitely going to marry my brother since we are not related by blood! She has dreamed of marrying her brother since she was a little girl. One day, however, she discovers that her brother is a character in a death game manga, and a year later, he holds a death game involving her classmates. In the process, he kills his...