Another plot could involve Harry going to America on a mission. There could be a dark wizard in America causing trouble, and the British magical community sends Harry as their best hope to stop this threat. Along the way, he teams up with American wizards and witches and they learn from each other's strengths and weaknesses.
Maybe Harry leaves for America to escape the fame and the constant reminders of his past in the UK. In America, he could start anew and try to live a more normal life. He could meet new friends who don't know about his heroic deeds in Britain and form relationships based on who he is now, not what he's done.
One possible plotline could be that they leave to escape the chaos in the wizarding world of Britain. Maybe they are seeking a fresh start in America where they can explore new magical cultures. For example, they could be interested in learning about the different types of magic practiced by American wizards and witches, like the use of wands that are made from different materials compared to those in Britain.
In some fanfictions, it might be that Severus leaves due to some external threat that he believes will harm Harry and the unborn child if he stays. So, he sacrifices his relationship with Harry for their safety. Harry, on the other hand, is left heartbroken but determined to raise the child alone. Later, Severus might return when he realizes he can protect them after all, leading to a reconciliation.
One possible plotline could be that Harry, traumatized by the events related to Azakaban, decides to leave Britain to find a new start. He might travel to other wizarding communities in Europe, like in France. There, he could discover new magical creatures and spells that are not well - known in Britain. He may also meet other witches and wizards who have different views on magic compared to his British counterparts, which could lead to his personal growth and a change in his understanding of the wizarding world.
One possible main plotline could be that Harry flees to America to escape the remaining Death Eaters in the UK who are still after him. In America, he might discover a new magical community with different rules and cultures. He could encounter new magical creatures and spells that are unique to America.
One possible plotline could be that Naruto discovers some long - lost secret about his mother Kushina and decides to leave the village with her to explore this mystery further. Maybe they are on a quest to find some hidden power or knowledge that is related to Kushina's Uzumaki heritage.
One possible plotline could be that Naruto leaves with Tsunade on a mission to find a rare herb that is said to have the power to heal any wound. Along the way, they face various enemies who also want the herb for their own malicious purposes. Naruto's skills and Tsunade's wisdom would be put to the test as they battle their way through.
Another plot could involve a sort of magical exchange. Orochimaru, being a master of some dark and strange jutsu in his own world, might offer to teach some of his knowledge to certain dark wizards in the Harry Potter world in exchange for something valuable. Harry Potter and his friends would have to prevent this knowledge transfer as it could tip the balance of power towards the dark side in their world. They might need to seek help from some of the more powerful and wise wizards like Dumbledore to outwit Orochimaru.
Another plot could involve Medusa being a part of a long - forgotten magical mystery that is somehow related to Harry's destiny. Harry, with his inquisitive nature, starts to research about her. As he gets closer to the truth, he has to face the danger of being turned to stone. But through his courage and the help of his friends, he manages to break the curse on Medusa, and in return, she helps him in his fight against Voldemort.
One possible plotline could be that Uncle Matthew Potter has some long - lost magical power or artifact that the main characters need to find. This could lead them on an adventure through different parts of the wizarding world. Another plot could involve him having a secret connection to a dark wizard from the past, and the story could be about uncovering this connection and dealing with its consequences.
One possible plotline could be that Naruto is somehow tricked into leaving with Kisami and Itachi. Maybe they convince him that there is a greater threat that only they can help him face. Along the way, Naruto might start to learn more about their motives and the secrets of their pasts. He could also be in a position where he has to use his own skills and values to influence them.