At a casino in Los Angeles California, two villains cause an explosion and escape with million's of dollars. The larger villain stirs up havoc in the city by rushing through crowded streets to escape.
Elect Plant blasts the larger villain with a bolt of lightning. Cow Lady transforms into her cow form but the villains quickly retaliate with a missile barrage. The monstrous villain leaps away and jumps on course to crush innocent people trapped in their car. 
A young unknown hero swiftly intercepts the villains and uses his awesome strength to send them crashing away with a single punch. He reminds the family that everything is okay because he is here now. The villains recover and the man clad in red demands to know who's interfering with his escape plans. The young hero simply states that he is a hero from Japan, and was just passing by.
The red villain fires his twin missiles at the hero but he simply uses the wind pressure from his blows to swipe them away. The young man looks too awesome while doing it and loses track of the villains. The large one leaps away, quickly fleeing the area.
David Shield rides in on the Allmobile and tells his friend Toshinori to climb aboard. David uses a sky drone to track the villain's movement and pursues them at high speeds. The villains try to stop their pursuers with a barrage of missiles. The All Mobile counters with its own projectiles containing bubbles that trap the missile blasts. David reminds Toshinori that they're going to be late for class and the latter leaps high into the air after the villains.
The villains scale the side of a large building but are no match for Toshi's speed. Annoyed, the red villain fires off more missiles. This time Toshinori counters with his Detroit Smash Super Move, sending a shockwave that forces the projectiles to detonate on each other. The explosion knocks the large villain off balance, causing him to grasp onto a building. While the villains take a moment to catch their breath, Toshinori continues his pursuit.
Toshinori propels himself off a building and is surprised by a well-hidden missile ambush. He uses air pressure to detonate the missiles and the blast burns his clothes away. From the fire leaps out Toshinori clad in his hero costume. The villains rush straight for him and Toshinori decides he'll end the fight using a move named after David's home state. The young hero counters the villains with California Smash, a powerful attack that sends the criminals crashing down into the city below. 
LA's Villains lay defeated in the imploded road. Toshinori laughs, celebrating his victory from the roof of a building. Elec Plant, Cow Lady, and other bystanders wonder who the yet unknown hero is. David Shield reveals his name is All Might, a student from Japan. He claims one day soon All Might will become the world's greatest hero, a Symbol of Peace.
David and Toshinori leave the scene of the battle. Toshinori claims the costume David created for him let him end the battle earlier. David says they can't afford to be late again but gets interrupted by the radio. Toshinori hears a report of a plane hijacking over the police scanner and tells David to go there. David knows this will make them late, but he also knows All Might can't ignore those in need.
The All Mobile merges with the air drone transform into its flight mode. The duo takes off into the skies to save the day once again.