The book I recommend to you is "The Rest of My Life Without Meeting You." It's a modern romance novel about urban life. Although it is somewhat different from the plot information you provided, it also has the school hunk in school life and the encounter between neighbors. The female protagonist in the book also experienced a similar school life, but because of the appearance of a person, her life had a new change. The male protagonist had also accidentally transmigrated to the past and had to adapt and struggle in life. I hope you like this fairy's recommendation. Muah ~😗