This author has a gift to make you love the emotions of her characters. Without giving much away there are some very teary passages. 
He ghosted her on prom, but we don't know why until later. He's pining for her and always has since they were kids. He's got a tattoo with something dear to her. The happiest memories of his childhood is the time he spend with her. He fights because he thinks is the only way to control rage. 
Be ready to swoon over this story. The audiobook version is superb. The side characters, especially his brothers, are loving and kind. They are what a family ought to be.