[Yandere + Fishing + Hidden Guard]
The princess Xiao Yanzi is about to marry a sickly prince.
Her secret guard, Ertai, was gentle and harmless, spoke softly, and behaved like a dog when he knelt in front of her.
She climbed the wall, and he continued. When she gets into trouble, he gets in trouble. She wants the stars in the sky and he can move the ladder.
She thought he was a sincere slave.
No one could save her until she was poisoned by a strange poison. He came back covered in blood, fed the antidote into her mouth, cut his wrist, and dropped the blood on her lips:
"Princess, this antidote requires the blood of a living person."
"From now on, you will bleed the same blood as me. I gave you your life. We will never be separated again."
Only then did she realize that she was the prey from beginning to end.
[Female A and male O, in fact, male A is so explosive]