MTL - Honkai Q&A, Starting with Kiana - Chapter 277

Finally caught up with the trend of crossing. Wait, everyone else has a golden finger when they cross, how can I become a little beggar after crossing!

Fortunately, the memory is still there, watching how I transformed from a little beggar to a top rich man!

- Description from novelbuddy

Zheng Tan somehow returns to the year 2003, turning into a black cat. Picked up from a rubbish heap by the Jiao family, he is given the name “Charcoal”, and so begins the life inside Professor Jiao’s family. Zheng Tan remembers that he was once a person, but currently his body is that of a cat. He has no way of speaking the human language, but can understand it, and even retains the thinking and IQ of a young 20 year old youth. Read along as he adapts to this new world, and somehow tumbles from a group brawl to catching a thief.

- Description from Novelupdates

Shen Yinning was originally the Crown Prince Lu Ying's childhood sweetheart and fiancée, but due to her father and brother's rebellion, she was exiled to Gan State and married to a minor local official as the daughter of a criminal. Meanwhile, Lu Ying gloriously married her cousin Shen Yunxi as his Crown Princess Consort.Three years later, Shen Yinning returned to the Capital with her husband. Everyone praised the Crown Prince and Princess for their mutual respect and harmony, and Shen Yunxi often flaunted in front of her how loving she and the Crown Prince were. However, only Shen Yinning knew that the seemingly restrained and honorable Lu Ying came to her chamber every night, completely disregarding the fact that she was now someone else's wife, secretly claiming her and keeping her as his Forbidden Fruit...

In childhood, they were neighbors. Xie Zhen always bullied Li Yu.