One interesting plot could be Gohan trying to balance his Saiyan powers with high school life. For example, he might accidentally use his super strength during gym class and have to cover it up.
A really engaging plot could be Gohan facing off against a new villain who targets the high school. Gohan has to protect his classmates without revealing his true self. He might have to use his intelligence to outwit the villain at first, like setting traps around the school. And when the time comes, he uses his hidden powers in a very discreet way to defeat the enemy.
Another plot could involve Gohan making new friends at high school who are completely unaware of his Saiyan heritage. He has to keep his identity a secret while also being a good friend, like when they get into trouble and he has to use his wits instead of his powers to get them out of it. This creates a lot of comical and tense situations.
In this fanfiction, Gohan might face the challenge of hiding his Saiyan powers from his classmates. He could also make new friends who are interested in different things like academics or sports, and he has to balance his high school life with his training as a Saiyan warrior.
Well, he might use his powers secretly. Like, he could use his super speed to be on time for every class without even breaking a sweat. And when there's a bully in school, he could give them a little scare with his strength, but not too much to expose his true identity.
A plot could be Gohan using his Super Saiyan 3 form to explore uncharted parts of the universe. He discovers new races and powers, and has to use his form to either protect or learn from them. For example, he might find a race that has a power that can enhance or even rival his Super Saiyan 3 state.
A possible plot could be Gohan focusing on his academic life more. Since he's neglected in the fighting and superhero side of things, he throws himself into his studies and becomes a super - intelligent character who uses his brain to solve problems in the Dragon Ball Z world that others can't with just brute force.
Obviously, Gohan would be the main character. Videl could also be in it as a classmate or a potential love interest. Piccolo might keep an eye on Gohan from afar to make sure he doesn't get into too much trouble. And of course, Gohan's friends from previous adventures could make cameo appearances, like Krillin dropping by the school sometimes.
Often, his friends at high school can be important characters too. They might be normal humans who are curious about Gohan's sometimes strange behavior. And of course, his family members like Chi - Chi could make appearances, maybe giving Gohan advice on how to balance school and home life.
A possible storyline is the characters forming a high school club related to martial arts or self - defense. They could teach other students and at the same time learn more about human relationships and teamwork. This would be a great way to see how they adapt to normal high school life while still having their unique powers and abilities.
There might be a fanfiction where Gohan and Towa form an unlikely alliance against a greater evil. In this story, Gohan could be learning some unique techniques from Towa, which would be really cool to read about as it combines their different powers and knowledge.
A third storyline could be about the high school students discovering the Dragon Balls. They might start off thinking they're just some cool artifacts, not realizing their true power. As they start to figure it out, they could get into all sorts of adventures, with the Z - fighters having to step in to protect them from those who would misuse the Dragon Balls.
One idea could be Gohan and Lime teaming up to face a new and powerful enemy that neither of them could defeat alone. They could train together, with Gohan teaching Lime some of his Saiyan techniques.