Meng Qiqi met "San'er". But not hers. But Meng Qiqi wished that "San'er" was hers.
Cao Chengxun caught a thief, but the aftermath made him feel guilty and wished he wasn't the one who caught the thief.
In short, this is a story about a male and female protagonist who forged an "evil relationship" because of the "mistress" incident.