Maybe they are in a witness protection program and have to live together. Harry could be a former detective who has some information on a big crime syndicate and Susan could be an accountant who unknowingly has evidence against the same syndicate. While living together, they initially clash due to their different personalities. But as they face threats from the syndicate trying to find them, they learn to trust and rely on each other, and in the process, a strong friendship develops.
Well, they might run away to a secluded forest. There, they could build a small cabin and start a new life away from the chaos of their normal world. Maybe they discover some magical creatures in the forest that help them survive.
Well, perhaps they could be forced to live together due to some magical situation. Maybe a spell gone wrong that binds them to the same living space. This would lead to them getting to know each other's quirks and gradually becoming friends or more.
Their relationship could start off rocky. For instance, if they have different cleanliness standards. Harry might be a neat freak and Susan more laid - back about cleaning. But as they communicate more, they start to respect each other's ways. Harry could learn to be more relaxed and Susan might make an effort to be tidier. This new - found understanding could lead to a deeper friendship where they share their secrets and fears.
Maybe they live together as part of a witness protection - like situation in the wizarding world. Some powerful and dangerous wizard is after them, so they have to stay together in a hidden, magically protected house. They learn to live with each other's quirks, like Harry's impulsive heroics and Hermione's strict study schedules, and in the process, they strengthen their friendship even more.
One possible plot could be that Harry and Daphne start living together due to some sort of special arrangement. Maybe they are on a secret mission together and need to stay in the same place to keep an eye on things. As they live together, they gradually learn about each other's habits and personalities. Harry might discover Daphne's love for a particular type of magic or her unique skills in potion - making. And Daphne could find out more about Harry's past traumas and his true nature as a hero. They could start off as just roommates but slowly develop a deep friendship or even more as they face various challenges together.
It could be that Harry and Susan are escaping some sort of danger in England. They leave secretly and head to France. There, they try to blend in with the local community. Harry might find work as a painter and Susan could start teaching English. Their journey would be about not only starting anew but also constantly looking over their shoulders in case the danger from England follows them.
In the fanfiction, it could be related to his relationship with Ginny or other important people in his life. If Ginny left him for some reason, like being under a spell or falling in love with someone else because of some magical interference. Harry, who has always been through so much, might see this as the final straw. His heartbreak, combined with all the past burdens, could make him lose the will to live. He might feel like there's nothing left for him in a world where he can't even have a happy relationship with the person he loves.
One possible plot could be that after the war, Harry and Susan cross paths while helping to rebuild Hogwarts. They start to work together on a project, like restoring the Greenhouses. As they spend more time together, they realize they have a deep connection and fall in love. Eventually, they get married and combine their families' traditions at the wedding, with Harry's wizarding world fame and Susan's Bones family heritage.
In a fanfiction, perhaps they meet during a Quidditch match. Susan Bones is cheering for her house, and Harry, being the Gryffindor Seeker, catches the Snitch right in front of her. After the match, she goes to congratulate him. They start talking about their different experiences in Hogwarts. Harry shares his adventures with the Chamber of Secrets and the Triwizard Tournament, while Susan tells him about her family's long - standing history in the wizarding world. As time passes, they become good friends and support each other through various challenges at Hogwarts.
One possible plot could be that Susan Bones is in danger during a Death Eater attack at Hogwarts. Harry, using his quick reflexes and powerful magic, manages to fend off the attackers and rescue Susan. Maybe he discovers a special connection between Susan and some important magical artifact that the Death Eaters are after.