Another possibility is that the Muggle male is related to a magical object or place in the Muggle world that has some significance in the wizarding world. Luna and Ginny are sent to investigate it. At first, he is skeptical of them, but as they show him real magic, he becomes fascinated. Together, they work to protect the object or place from dark wizards who also want to get their hands on it.
Begin with a conflict. Maybe the Muggle male has unknowingly gotten himself into trouble with a dark wizard. Luna and Ginny hear about it through the grapevine in the wizarding world. This immediately sets up a situation where they need to rescue him. You can then describe their first encounter, how Ginny might be more cautious while Luna is more curious about this Muggle in trouble.
A plot idea could be that the Muggle has a natural ability to resist magic due to some genetic quirk, which is related to his amnesia. Ginny, being interested in the study of magic and Muggles, tries to figure out how this is possible with Harry's help. They start to experiment with different spells and potions to not only restore his memory but also understand this unique ability of his, which could lead to some interesting discoveries about the relationship between magic and non - magic folk.
There's also 'Ginny's Muggle Adventure with Harry'. This fanfiction focuses on Ginny's perspective as she drags Harry into different Muggle experiences. It has a lot of humor as Harry is often clueless about Muggle ways at first, but through Ginny's guidance, he starts to appreciate and enjoy the Muggle world more.
One possible analysis is that it could explore a different side of the characters' relationships. In fanfiction, such a scenario might be used to show a deeper emotional connection between Ginny and Luna. It could also be a way to introduce new storylines or character developments that deviate from the original narrative.
Love and relationship development is also very common. Their relationship deepens as they face the challenges of the Muggle world together. For example, they might have to hide their magical abilities while in public in the Muggle world, which brings them closer.
A plot could revolve around the male reader being new to the magical school. Luna and Ginny take him under their wing and show him all the hidden nooks and crannies of the school. Along the way, they form a strong friendship as they face challenges together, like dealing with a strict teacher or a bully. It's a story about friendship and discovery. The three of them could also start a club together, something like a 'Magical Creatures and Their Habitats' club. They go on adventures to study different creatures, and in the process, their bond grows stronger as they learn more about each other and the magical world around them.
One great 'Harry and Ginny and Luna' fanfiction is 'The Trio's New Adventures'. It delves into their post - Hogwarts lives where they team up for a mysterious magical research. The interactions between Harry, Ginny and Luna are really well - written, staying true to their characters.
A plot could revolve around a school project where they team up. They decide to study a rare magical phenomenon that has been causing strange things to happen at Hogwarts. As they dig deeper, they realize it's related to a forgotten spell from the past. They face opposition from some students who think they're meddling in dangerous magic, but they persevere and eventually solve the mystery.
One interesting fanfiction could be where the Muggle with amnesia stumbles into the wizarding world and Harry and Ginny have to help. Maybe the Muggle saw something magical before the amnesia and there are dark forces trying to keep him silent. It could be a story full of mystery and adventure as they try to restore his memory and protect him from danger.
One plot idea could be that Ginny and Lily Luna Potter discover a hidden magical ability within the family that has been long forgotten. They embark on a journey to uncover the secrets behind it, facing various magical creatures and ancient spells along the way.