Chapter 1: Here's Sonic!
The story starts with Dr. Eggman attempting to escape from the police, and runs into our favorite blue blur. As he is being chased by Sonic, he runs into a pole since he was not looking where he was going, and then begs Sonic for mercy after confessing to robbing a bank. While Sonic is not looking, Eggman glues his feet to the ground (which he successfully pulls out) and Sonic goes after Eggman. The doctor attempts to blow up a building he calls "Sonic Motel", and winds up under the rubble himself. In a last effort, he brings out a machine called "Gokkuroach-kun", who he assigns to destroy all cockroaches (a.k.a., Sonic) The machine, however, mistakes Eggman for a cockroach and attacks him, and in the end, the robot explodes. Sonic then comments, "Scorched black...just like a cockroach."
Chapter 2: Which is the better combo?
Chapter 3: The real thing is uniquely different...?
Chapter 4: Treasure competition in South Island!
Sonic, Tails, Amy, and Knuckles visit South Island in search of a treasure. Amy claims it to be "the most romantic treasure in the world." They then spot Eggman in a motorboat, and Amy and Knuckles follow him underwater. The Doctor then, almost immediately after, gets swallowed up by a large shark. Knuckles and Amy hurry to the surface to tell Sonic, who comments that they should "...prepare the funeral, I guess." Just then, the shark attacks and destroys the boat, and Sonic falls into the water, with his inability to swim preventing him from resurfacing. The shark, revealed to be one of Eggman's mechs, fires a missile at Sonic and Knuckles, resulting in Knuckles knocking it away. Sonic and Knuckles come back up for air, with the shark on their tails. Sonic then runs across the surface (which, frankly, he could have done in the first place) while carrying Knuckles with him. The Shark Mech fires its dorsal fin at Sonic, only to have Sonic ride it like a surfboard, and slice the shark in half (also causing Eggman to be sent flying in the air, lose his fundoshi and hide behind his hands). The treasure revealed, the gang open up the chest to reveal Eggman's "Golden Fundoshi," which apparently is a treasure to him.