Dear Mr. Shi

Shi Yuhan is the most heartless and evil human Song Qinghuan has ever met. He's arrogant, sharp-tongued, ruthless, and heartless towards her. Yet, he asks (read threaten) her to marry him and she has no choice but to agree. She needs to get into the Era Group to investigate her elder brother's whereabouts. Will her sacrifice be worth it? Will she be able to find the truth of her elder brother's disappearance? Will Shi Yuhan continue tormenting her? What's his motive?