Sonic the Hedgehog 2: The Secret Admirer is a story book, written for children ages 4 through 8. It is set in the same continuity as Sonic the Hedgehog television series.
After escaping a horde of Dr. Robotnik's robots, Sonic returns to the secret headquarters of the Freedom Fighters, and prepares for a picnic. After scolding him for not cleaning his shoes, Princess Sally remarks that Tails loves to put large amounts of ketchup on all his food.
After arriving to the picnic late, they eat the food prepared by Antoine, the "best cook in Knothole Village". After eating, Rotor shows the others his new invention: the Smogsucker 2000, a device designed to store any smoke generated by cooking to prevent Robotnik from ascertaining their location.
On the way back to headquarters, they come across a basket containing "Solar Sugar Snap Snacks" and a note stating "I think you're keen!" Unable to agree to whom the note is directed, Sally hides the basket in the woods until they figure it out.
As Sonic mans the Spy-Scope, and Antoine stays in his room, they both imagine themselves as the obvious target of the note, recalling themselves as the hero of a recent attack on one of Robotnik's Buzz Bomber factories in which several prisoners were freed.
Sonic later finds Tails, and attempts to get him to man the Spy-Scope so he can "help Rotor clean his lab." He notices Tails is holding flowers, and bursts out laughing, unable to imagine Tails having an admirer. Tails' feelings are hurt by this.
Sonic then spots a message spelled out with rocks on a nearby hillside, and notes the poor spelling:
To my favorite Freedum Fighter:
Meet me at Mud Lake today.
Follow the trail of baskets and
you will find me. I think you're keen!
Meanwhile, Dr. Robotnik is in his lab, along with Snively and Cluck, angered that Sally placed the basket, which actually held a hidden camera, in the bushes. His plan was to use the camera to find the location of Knothole village, as well as to lure them to the lake with the 'keen' messages by dividing them.
Sonic then arrives at the lake wearing a tie, finding Sally, and mistaking her for his admirer. Tails, Antoine, and Rotor, each dressed up, arrive shortly after; they soon learn Sally did not place the basket. Robotnik zooms in, along with an army of Buzz Bombers. Tails frantically throws rocks at them, to no avail. They are surrounded.
Sonic notices Rotor has brought his invention, the Smogsucker 2000, and releases all the stored smoke, and spins rapidly, sending the smoke everywhere and attacking the Badniks while they cannot see. Watching his Buzz Bombers falling into the water left and right, Robotnik retreats.
Back at headquarters, they piece everything together. Sally complains that they never get dressed up as nice as they are now, at which point Antoine tells them to return the ties and stay out of his closet, to which Sonic remarks, "I don't ever want to be tied down anyway."
At the start, a sign listing Robotnik's rules is shown, one of which is "No Nintendo playing", a reference to Sega and Nintendo's rivalry in the video game industry during that time.