Xin Ruying, an angel-like girl known as the sweetheart devil, always has a faint smile on her face, which makes everyone crazy. She is a hunter of beautiful men, and none of her prey can escape. She is an obedient sweetheart when they are together, but a cruel devil when they break up. Underneath that kind and innocent appearance is a scarred devil's heart.
Ye Xin, Xin Ruying's cohabitant and good friend, has the same hobbies as Ruying, has also been emotionally hurt, and is known as the naughty devil.