User:Young Mako/Sandbox

Prologue
Several years ago, there was an attack on a Casino in California USA. Two villains, one blue and beastly and the other clad in red, escape from the scene and stir up a public panic. The police, Elec Plant, and Cow Lady and try to apprehend the criminals but they escape using their beastly abilities. The chaos threatens a family trapped in their car but a young unknown hero sends the villainous duo flying with a powerful punch.

The villains demand to know who they're fighting but the young man simply replies he's a hero from Japan. The villains attack with a missile barrage that the hero easily dismisses. The two criminals quickly flee the scene and David uses his advanced car to pick up his friend. Together, David Shield and Toshinori Yagi pursue the villains through town.

The red villain uses his missile Quirk only for David Shield's F-Unit car to counter with a shield of bubbles that trap the explosions. David reminds Toshinori they're going to be late for a lecture. Toshinori kicks it into high gear and chases the criminals up the side of a building. The blast from more missiles burns Toshinori's clothes away, revealing the hero costume beneath. All Might makes his debut in America in fashion by defeating the villains with California Smash!

Act One
All Might awakens from his dream of the past to his young protege calling his name. Izuku Midoriya wakes his sensei so they can look at I-Island together from the sky as their plane prepares to land there. Izuku is thankful he gets to visit I-Island at the beginning of the summer break. All Might is glad he invited young Izuku but the latter isn't so sure he belongs. He believes plus-1's should be reserved for family but All Might reassures him they are connected by something thicker than blood.

The plane starts its landing procedure and All Might shifts into his muscular form. He must maintain this form the entire time to keep his weakness a secret. All Might makes sure Izuku brought his hero costume along and they both exit the plane. As they pass through immigration, All Might asks Izuku what he knows about the island. Izuku starts muttering about I-Island's origin as a place for researchers to come together to study Quirks and create support items.

The I-Expo preopening is starting, and those with an invitation can gain access to an abundant showcase of incredible technology. People on I-Island can use their Quirks freely and many of the expo attractions use Quirks. While Izuku is geeking out over the beautiful view of the island, All Might gets swarmed by a crowd of adoring fans. The incident nearly makes All Might late for a reunion with an old friend.

All Might asks Izuku to meet his old friend but reminds him not to spill the details about One For All. Melissa Shield uses a pogo stick to approach "Uncle Might" before greeting him with a hug. All Might is happy to see Melissa has grown up into a young woman. Now 17, Melissa says she invited All Might to the expo to surprise her father as a gift because he's finishing up an important research project. All Might introduces Melissa to Izuku and she learns that he is Uncle Might's student. Melissa starts asking Izuku about his Quirk and checks out his costume, all while making Izuku uncomfortable. She also notices the scars on Izuku's hand but All Might reminds her about their agenda.

Meanwhile, a mysterious group of men overlooks the airport lobby. Their leader talks to someone on the phone and confirms they infiltrated the expo and that "the goods" will arrive later in the day. In David's lab, he and Sam talk about how hard Melissa has been working on her own research. Melissa interrupts to reunite David with his longtime friend All Might.

David and All Might are very happy to be reunited. All Might introduces Izuku who immediately recognizes David Shield and geeks out over him being a top scientist in Quirk research. David is also the man responsible for all of All Might's costumes. David wishes to get re-acquainted with All Might alone and asks Melissa to show Izuku around the I-Expo.

The teenagers leave and Melissa asks Izuku what his preferred name is. He replies Deku and Melissa calls it a strange nickname. Meanwhile, All Might reverts back to his weak form and thanks David for getting everyone out of the room. David is surprised at Toshinori's state even after getting notified of what happened via email.

Izuku and Melissa notice Godzillo among other heroes that were invited to the expo. Melissa also asks if Izuku is attending the industry party later that day. Izuku believes this is why All Might made him pack formal clothes. Melissa brings Izuku to the pavilion where together they geek out over flashy support items developed for the expo. Izuku asks Melissa about how much she respects her dad and she replies that she wants to be just like him. Melissa is a third year at the I-Island Academy where students go to become scientists. She and Deku share the same goal of working hard to become like who they look up to.

Ochaco Uraraka suddenly interrupts Izuku's playdate alongside Momo Yaoyorozu and Kyoka Jiro. Izuku's classmates believe he's on a date but he tries to calm the situation down by explaining what happened. Melissa starts talking about All Might but Izuku stops her to remind her not to say anything. The five of them go to the cafe to have tea together where everyone gets better acquainted. Denki Kaminari and Minoru Mineta surprise their classmates by working as extra staff at the cafe.

Tenya Iida abruptly joins the party by running in to remind the boys to work harder. The Iida Hero Family received invitations to the expo but Tenya was the only one who could attend. Momo got invited because her family has stock in some of the I-Expo's sponsors. She got to bring Kyoka and Ochaco along with two extra invites. The other girls lost rock paper scissors and can't attend the I-Expo until it's open to the public. Melissa promises to show everyone around once the expo is fully open.

Izuku notices an explosion nearby and heads toward it. He arrives at the "Villain Attack" attraction while Eijiro Kirishima clears it in thirty-three seconds for eighth place. Next up, Katsuki Bakugo clears the event in only fifteen seconds and jumps into first place. Eijiro notices his Izuku and his other peers watching from the stands. Katsuki is annoyed by Izuku's presence and makes a scene. Eijiro tells everyone that Katsuki got invited since he won the U.A. Sports Festival and he just tagged along.

Izuku takes on the Villain Attack attraction next and manages to score second place with a time if sixteen seconds. Melissa notices that Izuku's destructive power is very similar to All Might's. Ochaco and Tenya praise Izuku for his performance, further annoying Katsuki. Suddenly, Shoto Todoroki clears the event in fourteen seconds and steals first place out of nowhere using his ice. Irritated, Katsuki flies to Shoto and gets in his face about why he's there. Shoto reveals that he was invited to represent Endeavor. Tenya puts a stop to their feud while Melissa says that all U.A. students are incredible.

Concurrently, the mysterious man from earlier receives the "goods" and learns All Might is on the island. David runs tests of Toshinori's broken body and learns that his Quirk levels are astronomically low. He asks Toshinori about it but he gives him a vague response. David worries that Japan's low crime rate of 6% will rise with the fall of the symbol of peace. All Might reassures him that the symbol of peace is still alive.

Melissa and the others regroup with Denki and Minoru. Melissa prepared invitations to the party of them and moves them both to tears. Tenya reminds everyone to meet up at the party at 6:30pm. Everyone disperses but Melissa asks Izuku to join her at her lab. Katsuki refuses to go to the party because he's unprepared but luckily Eijiro brought clothes for him. All Might shifts into his muscle form and leaves David's lab, promising to see him later at the party.

David recalls the first time he ever met Toshinori. There was an accident at his school where an experiment caused an explosion that set fire to the building. Toshinori saved all the people trapped inside from the blaze. David greets Toshinori and learns he's trying to become a hero. David creates a costume for All Might to use as a hero. From that point on, they worked together to suppress villains and worked as heroes during All Might's young age. All Might shared his dream of acting as a symbol of peace for the world with David.