The story of Sonic the Hedgehog 2.
Sonic the Hedgehog was looking for new adventures when he discovered West Side Island. Sonic landed his personal plane, the Tornado, on the island to check it out and relax, not paying attention to the fact that a certain metallic flying object was chasing him and suspiciously landed on the other side of the island.
It is said that a very long time ago, the people of West Side Island used a mysterious stone to advance their civilization and achieve prosperity. However, when those people tried to use the stone for the wrong reasons, their prosperity vanished overnight. It is believed that the kami sealed away the stone within the island's depths.
One day shortly afterward, Sonic noticed a shy orange fox tagging behind him, who nervously scurried back into the welcoming shade of the still palm trees when he was spotted. When Sonic was not looking, the peculiar fox barely managed to keep up with the blue hero. The fox's name was Miles Prower, though he was known as "Tails" due to his two special tails, which often made him the target of bullying. However, something changed in Tails when he saw Sonic come to the island, and he made up his mind that he wanted to be cool like Sonic. Realizing that the young kid was harmless, Sonic made friends with him and allowed him to hang around as he freely explored the island.
In Sonic Origins, this first meeting is shown differently with the introduction cutscene, with Tails being cornered by two bully foxes, who target him for having two tails. As the two bullies were messing with Tails' two tails, Sonic rushes by and sends the bullies spinning into a daze. With the bullies down and out, Tails, realizing he had been saved from the bullies, runs after Sonic, who takes notice of him, inviting Tails to come along. In the process, Tails discovers his two tails give him the ability to fly, with which he uses to catch up with Sonic.
On an early afternoon, Tails discovered a lone aircraft stranded at the beach. Being a budding fan of machinery and vehicles, he rushed to take a closer inspection. He was admiring its magnificent build until he noticed that Sonic was taking a nap under its wing. Realizing that Sonic owned the plane, Tails gently retreated to the other side of it so as not to wake him. Suddenly, an ominous flash occurred in the direction of the nearby forest, followed by a terrific explosion. The wild fire blew away various debris, which Tails avoided by taking cover underneath the Tornado as he witnessed robots violently excavating the area. This ceaseless activity threatened to blanket the entire island in its destructive flames.
It turned out that Dr. Robotnik detected the presence of all Chaos Emeralds after following Sonic, including the lost seventh one spoken of in the island's legend. He took the opportunity to kidnap the island's animals to rebuild his Badnik forces and finish his ultimate weapon, the Death Egg. Robotnik now ruled the factories, refineries and cities. He's grabbed control of everything except the seven Chaos Emeralds. The speedy hedgehog went off into the forest to set things right and the curious fox followed.
The heroic duo traveled through West Side Island, rescuing the kidnapped animals and stopping Robotnik's creations every time they face him. After liberating the island from Robotnik's control, the doctor took off to his flying fortress with Sonic and Tails following on his trail on the Tornado. However, the plane gets shot and Sonic has to continue on without Tails. After defeating Robotnik, the doctor retreats to the Death Egg but Tails returns with an upgraded Tornado allowing Sonic to catch up with the doctor. Onboard the space base, the two then have a climatic showdown with Sonic emerging victorious and the doctor defeated, causing the Death Egg to explode while Sonic escapes just in time falling through the Earth. He is then saved by Tails where the duo became best friends from the course of the adventure.
