The 'little big three' could be facing typical school problems like bullies. But being the special characters they are, they use their unique skills or personalities to stand up to the bullies and in the process, they make new friends who join them in their little group. They also might participate in a school competition, like a science fair or a talent show, and through their teamwork, they come up with an amazing entry that wows everyone in the school.
Since it's not specified, they could be three kids with extraordinary abilities or personalities. Maybe one is really smart, another is super athletic, and the third is extremely creative.
One possible plot could be that a mortal accidentally stumbles upon the realm of the little big three. They initially get frightened but then start to form unique bonds with each of the three. For example, they might teach one of them about modern mortal culture, which in turn helps the little big three in some unexpected way, like solving a long - standing problem in their realm.
Perhaps the Big Jet gets kidnapped by an evil character. So, the Little Einsteins embark on a mission to rescue it. Along the way, they face various challenges and make new friends who help them in their quest.
One interesting plot twist could be that when the big three go back in time, they find out that their actions in the past have unexpected consequences on their present selves. For example, a small decision they make in the past ends up changing their relationships with each other in the present in a major way.
Well, one possibility could be that they are turned into animals as a form of punishment. For example, Zeus could be turned into a peacock, Poseidon into a seahorse, and Hades into a black dog. Then they have to figure out how to reverse the spell while dealing with the challenges of being in animal forms, like Zeus having to deal with not being able to fly as high as he used to in his peacock form and facing threats from other animals.
One possible plot could be that the Big Three - Mirio, Nejire, and Tamaki - are transported to an alternate universe where they have to team up with their counterparts from different versions of BNHA. They face new villains and challenges that require them to combine their unique quirks in unexpected ways. For example, they might encounter a villain who can manipulate time, and they have to figure out how to use Mirio's intangibility, Nejire's wave motion, and Tamaki's transformation quirks to stop the villain before he destroys the fabric of the universes.
Well, it could be that the high school is built on an ancient underwater kingdom. Ariel, being a mermaid, senses the connection to her underwater heritage. She forms a club at school to study the history of the place. But there are other students who think she's just being weird. However, as she delves deeper, she discovers a way to bridge the gap between the mermaid world and the human high school world, all while dealing with typical high school drama like exams, prom, and friendships.
Friendship is a very common theme. The 'little big three' are often depicted as having a strong and unbreakable bond. Another theme is growth, as they face challenges and develop as characters. And adventure is also common, with them going on various quests or exploring new places.
The main characters could obviously be the mortal. It could be a young adult, say a college student who is curious and adventurous. Then there are the little big three. They could be characters with distinct personalities. For example, one could be really mischievous, another very wise, and the third one could be super strong but a bit naive.
One plot could be centered around a family secret. The big sister discovers that she is part of a long line of women who can grow to a giant size. She has to keep it a secret from everyone, including the little sister. However, one day the little sister accidentally finds out. At first, she is scared, but the big sister explains everything. Together, they use the big sister's ability to help their community, like saving it from a flood by building huge dams in her giant form.