Hinata would probably be extremely shy at first. She might blush furiously and be at a loss for words. After all, she has had a crush on Naruto for a long time, so it would be a dream come true for her.
She might immediately go to comfort him. Hinata has always cared deeply for Naruto, so seeing him cry would likely trigger her protective and empathetic side.
Hinata might react with anger. She's a strong - willed character deep down. So she could confront the person who cheated on her head - on. She might yell and express her disappointment and hurt. This would show her growth from a shy girl to someone who stands up for herself.
In the original series, Sakura was in love with Sasuke. But in a fanfiction where Naruto is married to Hinata, Sakura's reaction could be one of pure friendship. She might be happy for Naruto and Hinata because she sees how they are good for each other. For example, Hinata is very gentle and supportive of Naruto, which is different from Sakura's more headstrong relationship with Sasuke.
He could be deeply hurt. Naruto has a big heart, and Hinata has been an important person in his life. Her abandonment might make him question his self - worth. He might go into a bit of a slump, not being as enthusiastic as he usually is. But then, he's Naruto. He'd probably eventually pick himself up and try to figure out a way to either get her back or move on with his life in a positive way. He might also wonder if there's some greater danger or threat that he needs to deal with that caused Hinata to leave.
The fanfic could show Naruto's initial anger and confusion clearly. For example, having him raise his voice and ask Hinata how she could do this to him. Then, it could gradually show his sadness seeping in as he realizes the relationship might be over.
In a way, it has roots in real-life situations. However, like many movies, it might have taken some artistic liberties to make the story more engaging and cinematic.
Concrete Cowboys is not a true story. It's likely inspired by various elements but doesn't represent real events or people. The plot and characters are crafted to engage the audience within a fictional framework.