MTL - My Sister is Very Obsessive - Chapter 689 : like a mentally retarded

The Special Investigations Unit is a covert organisation that no-one in the city knows about, dedicated to investigating bizarre occurrences beyond the comprehension of the living. The Chief Zhao Yunlan isn’t a simple guy either, being the inheritor of the Guardian Order, he has always been a righteous conformist, excelling between realms of the living and the dead. While investigating a school suicide case, Zhao is attracted to the calm and reserved Professor Shen Wei, but the Professor seems to be rather fickle towards him…

- Description from Novelupdates

He was aloof, reticent, and indifferent to women. Many girls expressed their liking for him, but he refused all with three sentences: “No way,” “No need,” “No possibility.”Except for one person—her.Since she moved in and lived with his family, he changed a lot. The used-to-be aloof guy not only helped her with her homework but also protected her all the time. He liked to tease her every day.“Be good. I'll let you kiss me.”“I will only answer your questions.”“One wrong letter, one kiss.”

Wei Yuewu is the unloved daughter of the powerful Marquis Hua Yang.

On her way back to the capital city to marry her fiancé, she becomes the target of a ruthless assassination led by her fiancé, Marquis Jing Yuan.

With the help of the Prince of Yan State, she narrowly escapes from one disaster after another and returns to the capital.

Determined to avenge her enemies and unravel the mystery surrounding her engagement with Marquis Jing Yuan as well as the death of her mother, Wei Yuewu makes a deal with the Prince of Yan State.

However, just as she has triumphed over all her enemies and is about to reach the acme of her life, she deliberately destroys her own future and becomes an exile of her own…