In the fanfic, Harry might cry because he's now faced with the reality of having to rebuild his life. Before the war, his focus was mainly on fighting Voldemort. But after the victory, he has to figure out things like his career, his relationships, and his place in the new wizarding world. The pressure of all this new stuff can make him cry.
It could be that during the war, Harry had to be strong for everyone around him. After it's over, he no longer needs to hold up that façade. He might cry as he remembers all the times he was scared but couldn't show it, and all the people he had to be brave for. Now that the war is over, he can finally be vulnerable and let his emotions out.
One possible reason could be unrequited love. In the fanfic, Chansung might be in love with someone who doesn't feel the same way. This could lead to a deep sense of sadness and cause him to cry. For example, he might have confessed his feelings but been rejected, leaving him heartbroken.
Well, it could be that he's feeling the weight of his destiny. Harry has so much on his shoulders, like fighting Voldemort. Maybe he just had a particularly tough encounter with the Dark Arts or lost someone dear in the fight against the dark side. Another reason might be his feeling of isolation. Despite having friends, there are times when he feels alone in his battle.
It could also be that Harry himself is so traumatized by the war that he isolates himself. He might push people away, thinking that he's a danger to them. As he withdraws, others might misinterpret it as him not wanting their company and gradually abandon him.
One possible reason could be miscommunication. Maybe Harry made a decision during the post - war rebuilding without consulting Ginny, and she felt left out or disrespected. For example, if he agreed to some dangerous mission without telling her.
Well, it could be due to the stress of their relationship. Harry had a lot on his plate, being the hero and all. Ginny was also a strong - willed witch with her own ideas. They might have had an argument about their future together. For example, Harry might be worried about Ginny's safety if they stayed together, given his dangerous life. Ginny, on the other hand, could be frustrated that Harry was trying to push her away for her own good. Another possibility is that they could be crying over the state of the wizarding world. After all the destruction caused by the war, seeing their beloved Hogwarts in ruins or the wizarding community divided could be heart - breaking for them.
Maybe Harry is crying because he misses his parents. He often feels the pain of their absence deeply, and in this fanfic, when Sirius sees him, that could be the cause.
One reason could be failure. For example, if she fails in a magic experiment that she has been working hard on, it might lead to her crying as she is often very dedicated to her studies and magic practice.
Maybe the fight in the fanfiction was really intense and emotional. It could be that Harry's character was deeply hurt by the words or actions of the Louis fanfiction character. Fanfictions often create extreme situations that can tug at the heartstrings.
One possible reason could be that Ginny has seen Harry change a great deal during the war. Maybe the war has left Harry with a lot of emotional baggage that he's not dealing with well, and Ginny doesn't know how to handle it. So, she decides to give him some space by ignoring him for a while.
One possible reason could be that Harry has post - war trauma. He might have seen so much death and destruction during the war that he doesn't want to bring his darkness and pain to the Weasleys. He may think that staying away is a way to protect them from his own emotional turmoil.