How Did the Substitute Become His One and Only?

[Modern romance + domineering CEO + sweet romance + marriage first, love later + contract marriage + five-year age gap + hero planned it all along + heroine doesn’t realize] Lin Mianmian never imagined that an ordinary office worker like her could become a powerful man’s stand-in for his unattainable first love. Her job was to be the secretly married Mrs. Mu Yihuai, for one year under contract. After a year, she’d get a luxurious apartment in the city center and one hundred million yuan. Lin Mianmian: Wasn’t this basically being kept? But then again, they’d just gotten their marriage certificate. It wouldn’t be bad if she and the CEO became a real couple. Lin Mianmian quickly put that thought out of her mind. She absolutely couldn’t upset her benefactor. Every day, Lin Mianmian stayed professional and played the role of Mrs. Mu. But why was Mr. Mu looking at her more and more strangely? Weren’t they supposed to be a contract couple? When the contract expired a year later, Lin Mianmian was reluctant to leave, but she took the bank card her assistant had given her and the property deed, then left the villa. Three days later, Mr. Mu appeared at her door holding a diamond ring the size of a pigeon’s egg. Mu Yihuai: “Mianmian, will you truly marry me?” Lin Mianmian asked in surprise, “What about your first love?” Mu Yihuai smiled tenderly. “There was never a first love. You’ve always been the one I loved.”