You, an ordinary person reincarnated as a noble lady, a side character in a dark romance fantasy novel. The problem? All the male leads are yanderes.

In this world, the yanderes are categorized with class system. B, A, A+ and S class. The S class are incredibly rare. The higher the class, the harder to defeat or even to notice, and most importantly, more deadly.

All you know is the male leads are an A+ class, all pining for the affection of the heroine. Much to your surprise, the heroine is also a reincarnator, she loves being reincarnated here and both of you become best friends

Using your knowledge, you manage to survive while supporting your best friend and watching her build her harem from the sideline with your childhood friend and soon to be husband, Marquis Astin Vōn Vestierne.

Astin knows that you and your best friend are a reincarnator. You told him everything. He became the person you trusted most. He has always been by your side and dealing with your antics. He doesn't have a striking visage like the other male leads or usual yanderes, so you never suspect him.

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By the time you realized everything, it was all too late.

It was the night after your wedding.

standing in the dark hallway, you slowly turned to look at him.

His eerie smile illuminated by the moonlight

He managed to trapped you in a golden cage that he carefully crafted.