The female protagonist had a fondness for the male protagonist's modern novels since she was young?

The female lead was much younger than the male lead.
When the male protagonist was in high school, she was only an elementary school student.
The story began when the mistress returned from abroad.
Because of the misunderstanding with the male lead when she was young (that is, seeing the male lead being intimate with someone else), she decided to ignore him, but the male lead had to come to pick her up.
There seemed to be a housekeeper in the story. A long time ago, she had told the male protagonist to ignore the female protagonist (who seemed to be less than ten years old) and would lose her forever.
In the end, after many twists and turns, the female lead finally told the male lead that she had been angry all these years because she had seen him being intimate with other girls.
The male protagonist explained that he was in the prime of his life at that time and it was really difficult for him to restrain himself. He did not expect the female protagonist to be angry about something that happened when she was young and even ignored him.
The content was roughly like this. Do any experts know the title of the book? He could also introduce similar novels! Thank you, I've been looking for it for many years...
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Part of the plot of the novel
Nü Zhu (a primary school student) hoped that Nan Zhu could spend more time with her. She deliberately asked Nan Zhu if he knew how to do arithmetic homework. In fact, it was just a primary school homework. Nan Zhu, who was much older than her, knew how to do it. Nü Zhu only hoped that she could exchange it for more time with Nan Zhu. Unfortunately, the male character initially promised to teach her, but later it was not done. The fragile female character was disappointed and angry. She felt that the male character was no longer the big brother who loved her and often accompanied her. The distance between the couple grew further and further because of these small matters. Unfortunately, the male character did not realize that he had unknowingly hurt his little sister...

Answer 1

I recommend the book "The Nation's First Love: The Prince Charming Is Too Cold" to you. The female lead here, Mo Xiaoqing, has also liked the male lead, Ji Muhan, since she was young. This was a modern romance novel about urban life. It was about the love story between Mo Xiaoqing and Ji Muhan. Although Ji Muhan looked cold and heartless on the surface, he was slowly moved by Xiaoqing's perseverance. I hope you like my recommendation, Mwah ~😗