Sonic the Hedgehog was the name of a serialized comic strip that appeared in the anthology Shogaku Yonensei. Translating literally as "Fourth Year Student," it was published by Shogakukan, one of the largest publishing houses in Japan. Starting sometime in 1992, it became the first Sonic the Hedgehog storyline outside the direct influence of Sega, which allowed a freedom that the games would not be otherwise able to traverse. Written by Kenji Terada and illustrated by Sango Norimoto, the strips were aimed toward a younger demographic, and most likely meant to tie into the hype concerning Sonic the Hedgehog 2.
The series followed the adventures of Nicky, a young, bookish-looking hedgehog who through some manner was able to transform into the actual hero of the story, Sonic the Hedgehog. When being the blue hedgehog, he would be joined by Miles "Tails" Prower, his protégé, and the two would work together to stop Dr. Eggman and whatever evil schemes may be up his sleeve.
While the escapades of Sonic were the highlight of the strip, his alter-ego Nicky was provided with his own full cast of supporting characters. Nicky lived in a world similar to modern day Japan, along with his family and friends. His parents were named Paulie and Brenda (Paulie, the father, dressed in clothing reminiscent of a fighter pilot), and he also had a little sister, Anita. Outside of his home life, Nicky's best friend was a pudgy hedgehog named Little John, and he also had a girlfriend, a blond colored hedgehog named Amy. It was this character that would be the inspiration for the game character Amy Rose, albeit not in the same function.
Rounding out the cast were the lizard brothers Anton and Matt Brooke, who would do nothing but try and cause trouble for Nicky and his friends. An early version of Charmy Bee was also featured in the comic, although it is unknown what role he played, beyond being a friend toward Sonic and/or Nicky.
Except for Tails, nobody knows that Nicky is actually Sonic the Hedgehog, neither himself.
Unfortunately, not much more about the series is known as copies of the original strips are extremely rare. Unlike the Dash & Spin series done years later by Shogakukan, the strip was never collected into volumes, remaining as a Shogaku Yonensei exclusive. It is also unknown how many issues the strip ran for, the only concrete fact being that there were at least six produced.
Sonic the Hedgehog Book - A book with strips featuring the Sonic manga characters, which may or may not have been in Shogaku Yonensei.
Sonic the Hedgehog 2 Strategy Guide Comic - An adaptation of the Sonic 2 Japanese storyline, done by the same creative team but sticking with the game canon.