Joey Apronika (ジョイ · アポロニカ Joy Aporonika ) is the protagonist of the manga series Samus and Joey and its sequel series, Metroid EX. He is introduced on the frontier planet Liberty with his grandfathers and a small community. He wishes to train with Samus Aran after she saved him from a Space Pirate raid, so he can protect his remaining family. Joey has three concealed wheels in each of his shoes that allow him to move and turn at high velocity, as well as climbing spikes that can project from the front of them.
Joey is a stubborn, brave yet foolish boy who wishes to become a talented fighter. He tags along with Samus despite her protests, and occasionally helps her out through either his speed or just sheer luck. He notes to Samus that he does not fear death. Joey also seems to be fairly resilient--Samus reluctantly fires a Super Missile near the boy, and is surprised when he survives.
He stumbles upon a shedded Space Pirate molt and uses it as a disguise to help Samus discover the Megaroid's location, but loses it when he enters the Pirate leader's chambers. He is then seen fleeing from the Pirates as Samus attempts to rescue him.
The Megaroid then proceeds to drain all energy from the ship, causing it to grow in size. He flies out of the ship's destruction using the rug as a glider. After Samus tries to destroy the Megaroid using the most effective tactic (Ice Beam/Missiles), it shatters into billions of crystals that multiply rapidly, engulfing Samus and heading toward the village. Joey equips himself with Space Torches as he fights for the village's survival, leading the creatures away from the village, to Mount Pagos. He finds the volcano inactive, and is about to die when Samus rescues him and reawakens the volcano by using a Power Bomb and Super Missile. She then states that she is leaving for space once again, and Joey cannot come with her.
While reflecting, Joey discovers a parcel in his father's grave containing his Field Knuckle, and a letter telling him to strike out on his own. Samus decides to allow him to accompany her on a visit to an acquaintance. They arrive in the junk shop of her friend Diesel, only to find him held hostage by Jealousy. Samus is forced to engage in combat with Jealousy's bodyguard Bomad, and the ensuing conflict destroys most of the shop and everyone but Samus, Joey, Bomad and Diesel. Samus kills Bomad and leaves Joey in Diesel's care. Diesel demands that Joey help rebuild the shop.
Joey then discovers a news report where his mother, Dr. Diana Apronika, was on a ship that had gone missing. He and Diesel set out to search for her, and they crash-land on an unnamed planet. Joey reunites with his mother after rescuing her from a large humanoid beast.
Returning to Diesel's station, Joey gets back to work and saves a robot under attack. The robot thanks him by offering him scrap for the shop. Joey names it U-ton and they become friends. However, Samus reveals that U-ton is actually Bioroid Delta III, a defective robot scheduled for dismantling that escaped and destroyed a demolition ship. Joey tries to reason with U-ton, who activates his nuclear ability and threatens to destroy the station. Samus destroys U-ton, telling Joey he must "always pull the trigger, even if it is painful".
In chapter 15, it is revealed that Joey has seen war: when his father was still alive, the two of them visited a planet on which a Bunker-Busting Annihilator had been used, leaving no one alive. This scene was permanently etched into Joey's mind, and he vows to ensure it never happens to anyone else.
Joey accompanies Samus and Diesel to the Extreme Galaxy in Metroid EX, in search of seven Data Capsules containing her stolen abilities. Along the way, he encounters Knight, a general of the Greed Corps, who takes kindly to him. He later discovers that Knight was a friend of his father. At the climax of the story, Samus bids farewell to Joey as she prepares to face the Space Pirate leader Greed. She reveals her true identity to him, which leaves him in shock, and encourages him to become a strong warrior. Reluctantly, Joey evacuates the base with Diesel.
Ten years later, Joey is older and a rather unorthodox member of the Federation Police Force, still using his Field Knuckle much to the chagrin of his captain. He is seen ending a hostage crisis at a school on a Galactic Federation world. Pete, the boy he saved admonishes him, believing that he could have handled the criminal himself. Joey reassures him that his turn as a warrior is yet to come.
"Calls himself Samus' first disciple. Wants to become strong like his father."
"A young boy who calls himself Samus's first disciple. Together with Samus, they form the ultimate team!