A Gaia Memories is a mysterious device resembling a USB flash drive that contains all of the Earth's knowledge of what it represents. This enables its user to become a Dopants, or in some special cases a Kamen Rider. Every Gaia Memory is adorned with the first letter of its name, stylized to reflect the powers it imbues on its user. For example, the Injury Memory (acquired by Simon and Charlie before the series begins) resembles a broken bone in the shape of the letter I. In order to transform into a Dopant, the Gaia Memories is first inserted into a device called the L.C.O.G (Living Connector Setting Operation Gun), also called a Connect Shooter, which then produces a USB port-like tattoo on the user's skin called a Living Connector. Whenever the Gaia Memories is pressed onto the Living Connector, it enters the user's body and transforms the user into a Dopant. It is possible to use a Gaia Memories without a Living Connector however a side effect is that the user would later suffer intense physical pain after several uses.
This direct insertion will eventually drive its user insane from its addictive influence, which is why special belts called Memory Drivers have been developed for use by high ranking members of the Museum to filter out these and other side effects. This weakens the Dopant visibly, as such high-ranking Museum members use some of the strongest Gaia Memories, identified by their golden colors, to more than compensate for this weakening. These Gaia Memories seem to be even more dangerous than regular Gaia Memories as hinted in the series. Despite the benefits, there are those who dislike the use of Drivers and would very much prefer the poisoning than being weakened, like Professor Gould. It also seems that when used excessively, the user will slightly gain the Gaia Memory`s powers as hinted when Sebastian who held the Terror Memory for at least ten years seemed to be able to intimidate others as well as flashed purple eyes when doing so.
Kamen Riders utilize Gaia Memories that have been refined such that they can only be used in specialized Memory Driver belts, and the Gaia Memories used do not enter the body and channels power through the Driver. These kinds of Gaia Memories were created by Shroud during her time as Felicia Gardenar. This refinement makes them resemble USB drives, rather than the ribcage design on Dopant Gaia Memories, but further weakens the power of the Memories, only allowing access to the Memory's full power during a Maximum Drive.
To defeat a Dopant, a Kamen Rider has to use one of its Maximum Drive finishing attacks to eject and destroy the Gaia Memory, resulting in what is called a Memory Break. Evolved Gaia Memories require a direct strike on its location within the Dopant's body to execute the Memory Break. If the Dopant does not have a Living Connector, a Memory Break will not occur, however the Gaia Memories will still be ejected from the user's body. Dopants who use Memory Drivers are not susceptible to Memory Breaks.
List of Gaia Drives
- Simon Holmes (left half side)
- Joker Memory: The Joker Memory, also known as the Ace Memory, allows the user to increase fighting potential and enhances the users reflexes significantly, becoming the Skill Warrior. When used, half of Kamen Rider Double Detective becomes the black Ace Left Half. When the Joker Memory is placed in the Maximum Slot on the Double Driver, it allows Kamen Rider Double Detective to split into two halves to deliver an elemental-powered Maximum Drive attack. The Joker Memory can also be used with the Lost Driver to allow Simon to individually transform into Kamen Rider Joker.
- Metal Memories: The Metal memory, also known as the Steel Memory or the Fighter Memory, empowers the user with great strength and magnified resistance to physical harm, becoming the Superpowered Warrior. When used, half of Kamen Rider Double Detective becomes the silver Fighting Left Half. When the Metal Memory is placed in the Maximum Slot on the Metal Shaft, it allows Kamen Rider Double Detective to infuse the tips of the Metal Shaft with an elemental-powered Maximum Drive attack.
- Trigger Drive: The Trigger Drive, also known as the Sniper Drive, turns the user into an expert marksman, becoming the Gun Warrior. When used, half of Kamen Rider Double Detective becomes the blue Sniping Left Half. When the Trigger Memory is placed in the Maximum Slot on the Trigger Magnum, it allows Kamen Rider Double Detective to fire an elemental-powered Maximum Drive attack.
- Charlie (right half side)
- Cyclone Memory: The Cyclone Memory, also known as the Windy Memory, allows the user to move at fast speeds, controlling the very power of wind, becoming the Windy Warrior. When used, half of Kamen Rider Double Detective becomes the green Cyclonic Right Half. Forms using the Cyclone Memory possess a Windy Stabilizer, a silver scarf hanging from the neck.
- Heat Memory: The Heat Memory, also known as the Hot Memory, empowers the user with the element of fire, becoming the Blazing Warrior. When used, half of Kamen Rider Double Detective becomes the red Heated Right Half.
- Luna Memory: The Luna Memory, also known as the Illusion Memory, allows the user to cast illusions, stretching limbs and bending gunshots, becoming the Mysterious Warrior. When used, half of Kamen Rider Double Detective becomes the gold Fantastical Right Half.
The Pseudo Memories are artificial Gaia Memories which power the Memory Gadget support robots, allowing them to switch between their Gadget Mode and their Live Mode.
- Stag Memory: The Stag Memory allows the Stag Phone Memory Gadget to switch between its Cell Phone Mode and Stag Mode.
- Spider Memory: The Spider Memory allows the Spider Shock Memory Gadget to switch between its Wrist Watch Mode and Spider Mode.
- Bat Memory: The Bat Memory allows the Bat Shot Memory Gadget to switch between its Digicam Mode and Bat Mode.
- Frog Memory: The Frog Memory allows the Frog Pod Memory Gadget to switch between its Speaker Mode and Frog Mode.
- Denden Memory: The Denden Memory allows the Denden Sensor Memory Gadget to switch between its Goggle Mode and Denden Mode.
- The Fang Memory, also known as the Fanged Memory, is a special Gaia Memory that was solely created to protect Charlie and act on his orders, enabling him and Simon to transform into Kamen Rider Double Detective FangJoker. It can change between its Live Mode, which resembles a Dromaeosaurid, and its Memory Mode, the top of which resembles a dinosaur's head. When used, half of Kamen Rider Double Detective becomes the white Fanged Right Half, enabling Kamen Rider Double Detective to fight like a berserker while altering the left half to match it in being animalistic in design. Being made to protect Charlie and act as his bodyguard, the Fang Memory shows up whenever he is in danger or whenever he calls for it. Unlike the normal transformations into Kamen Rider Double Detective, this transformation is initiated by Charlie and the process causes Simon to fall comatose and transfer his mind until they revert to normal.
- The Xtreme Memory is a special bird-like Gaia Memory that allows Kamen Rider Double Detective to become CycloneJokerXtreme by changing from Live Mode to Memory Mode in order to slide onto the Double Driver. It first appears when Charlie is in mortal danger from being attacked by the Weather Dopant, and it digitizes him where Shroud confronts him about his mission to save the Earth. The Xtreme Memory's powers come directly from the true Gaia Memory and are accessed through the Crystal Server on CycloneJokerXtreme. To initiate its Maximum Drive, the Double Xtreme Rider Kick, the Xtreme Memory is closed and then re-opened. A variation of the Double Xtreme, the Double Prism Xtreme, is where Kamen Rider Double Detective inserts the Prism Memory in the Maximum Slot of the Double Driver before closing and re-opening the Xtreme Memory. When Charlie dissolves after his final battle as Kamen Rider Double Detective, the Xtreme Memory which holds the data of his mind and body does as well. However, after Sally sacrifices her life, she brings back the Xtreme Memory which holds Charlie's body until his physical form is restored.
- Prism Memory: The Prism Memory is the Gaia Memory for the Prism Bicker sword and shield. It serves as a storage for other Gaia Memories powers and links the power of four Maximum Drives into one. When placed in the Maximum Slot of the Double Driver, it allows Kamen Rider Double CycloneJokerXtreme to execute the Double Prism Xtreme Maximum Drive.
- Compress Memory: A version of the Cyclone Memory created and used within the Nightmare Dopant’s dream world.
- Trump Card Memory: A version of the Joker Memory created and used within the Nightmare Dopant’s dream world.
- Accel Memory: The Accel Memory, or Acceleration Memory, is Kamen Rider Accel's primary Gaia Memory. This enables Ace to transform into Kamen Rider Accel and access his primary Maximum Drive, as well as allow him to assume Bike Form.
- The Trial Memory, also known as the Challenge Memory, is a special Gaia Memory that allows Kamen Rider Accel to become Kamen Rider Accel Trial. While in Memory Mode, the Trial Memory enables Kamen Rider Accel to transform; the transformation is complete once the light on the traffic light-like Trans-Signal goes from red to blue (with a 3-second countdown sound effect). While in its stop watch-like Maximum Mode, once the Maximum Switch timer button is pressed, Kamen Rider Accel Trial has ten seconds to perform as many attacks as possible, usually kicks and in one occasion, slashes, before pressing the Maximum Switch again to activate the Maximum Drive. If the Maximum Switch is not pressed within the time allotted, the Maximum Drive fails and Kamen Rider Accel's transformation is forcibly and painfully cancelled. To handle this, Kamen Rider Accel normally tosses the Trial Drive into the air as the Maximum Drive begins, pressing the Maximum Switch as soon as it is caught and declaring the time indicated when the timer is stopped. Later in the series, he gets a better grip on the timing to the point where he can stop the timer without tossing the Trial Memory.
- Engine Memory: The Engine Memory is a Gaia Memory that gives the Engine Blade its various powers. It is not a true Gaia Memory however, and its powers are linked to those of the Accel Memory. This allows it to have more than one ability, each based on a different type of engine: Steam, which creates a wave or wall of hot steam; Jet, which allows the Engine Blade to execute super heated slashes or fire a bladed energy wave; and Electric which allows the Engine Blade to perform electrically charged slashes or fire a bolt of electricity. (sub drive).
- Beetle Memory: The Beetle Memory allows the Beetle Phone Memory Gadget to switch between its Cell Phone Mode and Beetle Mode.
- Cyclone Memory: Ace is briefly lent the Cyclone Memory by Charlie to battle the Weather Dopant. When inserted into the Engine Blade, it allows Kamen Rider Accel to perform a wind-powered Maximum Drive strong enough to wound even the Weather Dopant.
- Skull Memory: The Skull Memory, also called the Skeleton Memory, is Kamen Rider Skull's only Gaia Memory, enabling his transformation as well as powering his Skull Magnum gun.
- T2 Joker Memory: Simon, having been given a Lost Driver by the spirit of Kamen Rider Skull, uses the T2 Joker Memory to first transform into Kamen Rider Joker. This Drive is later destroyed with the other 25 T2 Gaia Memories during the battle with NEVER, with the Lost Driver being lost as well.
- Joker Memory: Following the loss of Charlie, Simon uses his original Joker Drive to transform into Kamen Rider Joker once again, having been left a Lost Driver by Charlie. After Charlie's return, Simon still occasionally becomes Joker should Charlie be too occupied to join him as Double.
- Eternal Memory: The Eternal Drive was used by Hayden to first transform into Kamen Rider Eternal Red Flare.
- T2 Eternal Memory: The T2 Eternal Drive is used by Hayden to transform into Kamen Rider Eternal Blue Flare.
- Bomb Memory: The Bomb Memory is a refined Gaia Memory owned by Shroud, which she uses with her Shroud Magnum firearm. Its Maximum Drive shoots out a sphere of energy which splits into smaller spheres that explode.
- Terror Memory: This golden executive Memory is used via a Gaia Driver belt by Sebastian Gardenar to transform into the Terror Dopant. Destroyed by Kamen Rider Double CycloneJokerXtreme's Double Xtreme Maximum Drive.
- Taboo Memory: This golden executive Drive is used via a Gaia Driver belt by to transform Samantha Gardenar into the Taboo Dopant.
- ClayDoll Drive: This golden executive Memory is used via a Gaia Driver belt by Sally Gardenar to transform into the ClayDoll Dopant.
- Nasca Memory: This golden executive Drive was initally used, via a Gaia Driver belt, by Nevel Rattan to transform into the Nasca Dopant. Following his death at the hands of Samantha Gardenar, this Drive was later taken by her, using it directly via a Living Connector to become the second Nasca Dopant, evolving beyond the default "Blue Nasca" form assumed by Nevel to the R Nasca Dopant. Destroyed by ClayDoll Xtreme.
- Smilodon Memory: This golden executive Memory is used via a Gaia Driver belt by Mick to transform into the Smilodon Dopant. Destroyed by Kamen Rider Double CycloneMetal's Metal Stag Break Maximum Drive.
- Weather Memory: This Memory is used directly via a Living Connector by Professor Gould, who received it from Shroud, to transform into the Weather Dopant. Destroyed by Kamen Rider Accel Trial's Machine Gun Spike Maximum Drive.
- Utopia Memory: Given to Foundation X as part of their partnership with the Museum, this golden executive Memory is used via a Gaia Driver belt by Mr. Nelson to transform into the Utopia Dopant. Destroyed by Kamen Rider Double CycloneJokerXtreme's Double Prism Xtreme Maximum Drive.