- Written by Riku SanjoDirected by Hidenori Ishida
At the Drive Pit, Mr. Belt contacted his mentor, Professor Harley Hendrickson where he asked on why did Go returned to Japan. Harley furiously revealed that Go went out in the middle of his training and requested the team to look after him. According to Rinna, Mach is Harley's new system which was said to surpass Krim's Drive system. Kiriko furiously kicked the whole pit and yelled at Mr. Belt for hiding the fact that he planned to use her brother as his new candidate without her knowledge. Go even teases her sister and Shinnosuke (much to Rinna's jealousy) and ended up with both of them argued. The two siblings visited their father's memorial, Go resolved not to live with Kiriko due to his own behaviour and for her sister's safety, since they only had each other after their parents' death.
At the Special Investigation Unit, a group of robbers broadcast their next robbery Kuruma Credit Union and challenged the police forces to stop them since they had the same Slowdown bracelet which previously worn by Naoki Todagawa. Combined with Kyu's mentions that no Slowdown detections on radar lately, this means that Naoki's case was an example. About half an our before the robbery, Genpachiro and Shinnosuke interrogate Naoki on the information for whom had selling the Slowdown wristbands. Naoki revealed that he had no idea on who sold him the item, meaning those wristbands will automatically trigger a memory eraser to assure it's secret.
In the Roidmude's hideout, Medic revealed that Gunman and Roidmude 018 impersonated as a pair of major underworld traffickers. 018 sells the device and Gunman acted as his bodyguard. Heart sent Chase to guard 018 until he evolves. Chase agreed but he grew skeptical with his number and the point of him had no memories of Global Freeze. Genpachiro hired SWAT officers at Kuruma and the robbers on their way. But Go/Mach stopped them, released his own Heavy Acceleration and rob them of their Slowdown wristbands. Shinnosuke/Drive arrived and stopped him. Go surrenders as he switch off the Heavy Acceleration. He angrily scolded Go for using it despite his good intentions but Go calmly question him that they were even with the Roidmudes since both are powered by the same source.
Captain Jun returned from his vacation and Go appeared in the Special Investigation Unit by revealing his snapshot of Mach. Shinnosuke and the Drive Pit crews brought him away as Go explained that he got his Signal Bikes to capture his picture. Mr. Belt explained that, Mach Driver Honoh was made based on the aspects of Drive Driver but it also had its own AI much like Krim's role in Drive Driver. Shinnosuke suddenly realised something and sent the Shift Cars in a search for Go. Go at the same time quickly infiltrated the Roidmudes' base and destroy their Slowdown wristbands. As Gunman, 018 and Chase about to kill him, he was saved by Kiriko and Shinnosuke. The latter revealed that Go/Mach used Heavy Acceleration to remove the trio robbers' bracelet to interrogate their secrets before they lost their memory, since he had familiar with their operations back at America.
Shinnosuke as Drive transformed and battle Mashin Chaser while the Roidmude brothers attempted to attack the Shijima siblings. Mr. Belt realised that Mashin Chaser's number is 000/Protozero, hinting an upcoming secret. Signal Bikes came to aid Go and remove 018's Slowdown wristbands, figuring out that 018 had produced them. Go transformed into Mach and outsmart the two brothers. He assumed Mach Kikern and summon a demon beast to attack them. He switched to Mach Tomarle and finally Mach Kaksarn. He used Full Throttle to destroy their bodies followed by their Core as Mach Magarl. Before Mashin Chaser could attack Mach, Medic appeared and spirited him away. At the cafeteria, Shinnosuke started to accept Go's friendship along with the term big brother.
- Accidental Hand-Hold: Kiriko and Shinnosuke do this in the Drive Pit when reaching for some sweets.
- As You Know: Medic explains the Gunman Brothers' plan. For the audience, it's good to know, but she's talking to the other leaders, who of course know what their own scheme is. Sure enough, Brain grouses "I already know all that!"
- Big Brother Instinct: A major theme throughout the episode. We not only have Gou swearing to protect his older sister Kiriko, Shinnosuke becoming a big brother figure to him (in order to be his "brakes"), but also Gunman's and 018 relationship.
- Disproportionate Retribution: Gou is followed around by girls at the cafeteria, praising his photography skills and asking to see the Kamen Rider photos. When Kyuu also express the desire to see them, the females react by calling him "disgusting" and beating him up on the spot.
- Eye Scream: Kiriko shoots both Gunman and 018 in the eyes in order to distract them.
- Henohenomoheji: The fake bills that Gou fools 018 with have this kind of face.
- I Warned You: Played for Laughs. When Mach uses the Kikern Signal Bike, he warns the Roidmude brothers that it's going to be dangerous. After Kikern starts munching them, Mach pulls this trope.
- Lampshade Hanging: When Gou transforms and says his overly long catchphrase, his sister is less than impressed.
- Kiriko: Is he going to do that every single time...?
- Laser-Guided Amnesia: The Slowdown-inducing bracelets had this as a security measure, so that no one would spill Gunman and 018's secrets. Gou gets around this by using his own Slowdown to interrogate the thugs to slow down the bracelets' amnesia-inducing effects long enough to get info.
- Ship Tease: This episode contains a lot of teases regarding Shinnosuke and Kiriko... to the dismay of Rinna.
- Take Up My Sword: Mach has been designed to one day replace Drive. It does not sit well with neither Shinnosuke nor Kiriko. Especially Kiriko.
- The Roidmude Count: 88The Answer: Because no one can keep up with him.
