- Shotaro: Man... Philip is always a problem when he's obsessed with something.
- The C stands for "Cockroach" and "Client.
- The first part is subtitled "Phillip Can't Stand It"
- The second part is subtitled "Dancing Hero"
While doing some research in the Gaia Library, Philip comes across a locked book he cannot open titled "Heaven's Tornado", a street dance which leads him to Dango Inamoto. After realizing he cannot go any further without contacting the young man, Philip leaves the office to hunt him down with Akiko in tow. However after finding Dango and confronting him about Heaven's Tornado and showing his own dance moves, Dango refuses to tell Philip anything and leaves as the two follow to a public bus incognito. Shotaro, meanwhile, goes to investigate Kazehana High School after a note tied to a rock flies into the window prior to Philip's going out. After being confronted by the school's security, he runs to the principal when attacked by the Cockroach Dopant, calling Philip to transform into Kamen Rider Double. The Cockroach Dopant is nearly defeated after the two transform into LunaTrigger until Akiko sends the Stag Phone to tell Philip that Dango is getting off of the bus, allowing the Dopant to escape as Double gets into an internal argument. When Dango arrives to Kazehana High, he begins dancing to call out Chizuru Hoshino, his former dance partner, a fact that Philip takes into account when Dango's boombox is shut off by a teacher and the boy runs off in search of Chizuru. As Philip and Akiko follow Dango to the school's pool, they are suddenly attacked by the Smilodon Dopant who is out to capture Philip. Elsewhere, Shotaro meets with his high school informants Queen and Elizabeth, who show to him that the Cockroach Dopant's attacks are related to the "Dark Bug Exterminator" website and that the principal is not the intended target but Chizuru. Shotaro returns to Kazehana High, meeting with Dango just as Chizuru is attacked by the Cockroach Dopant who reveals that it was Dango who posted her name on the website. However, before Shotaro can transform into Double, Philip and Akiko have to escape from the Smilodon Dopant by jumping off of an overpass into a garbage truck. Once more, Kamen Rider Double LunaTrigger has the Cockroach Dopant in his sights when he is distracted by Dango and Chizuru fighting, giving the Cockroach Dopant the opportunity to steal the Luna and Trigger Memories right out of the Double Driver.
Losing the Luna and Trigger Memories, Kamen Rider Double is at a severe disadvantage against the Cockroach Dopant who man handles Double with his speed. Though Double uses HeatMetal to turn the tables, he loses the Heat and Metal Memories as well. Later, brought to the Narumi Agency by Shotaro, Dango reveals he was the one who threw the rock and that he posted on the Dark Big Extermination out of venting his rage when he and Chizuru broke up as she joined the swimming team without explaining herself. As Philip looks up Chizuru's reason through the Gaia Library, Shotaro meets up with Santa-chan for information about Cockroach Dopant, giving him a self-published manga that leads him to dōjinshi artist Ikari. Ikari speaks to Kirihiko on the phone, informing him of his possession of Double's Gaia Memories before taking the man's advice to take the remaining Gaia Memories and Double Driver for his own use. Shotaro confronts Ikari, seeking to retrieve the Gaia Memories until Ikari transforms into the Cockroach Dopant and escapes. Shotaro sends the Stag Phone to track him, but the Cockroach Dopant manages to ground it. Meanwhile, Philip finds Chizuru and brings her back to the office to force her and Dango into the RevolGarry so they can make amends. Though the two argue, Chizuru reveals to Dango that she only took up swimming to perfect her dancing and that she still shares his dream of becoming a great dance team. As they leave so Philip can watch Heaven's Tornado, Akiko receives a phone call from Shotaro's phone and tells him where they are going. However, the Cockroach Dopant is on the other line and shows up to break Chizuru's leg. Dango tries to fight him off as Philip interrogates Chizuru on the keyword for Heaven's Tornado: "Wave". With all of the knowledge of the dance at his disposal, when Shotaro finally arrives to fight the Cockroach Dopant as Kamen Rider Double, Philip uses his newly found dancing abilities with Dango to fight. They use Heaven's Tornado to attack the Cockroach Dopant, retrieving the Gaia Memories and transforming into LunaTrigger to deliver the final blow and leave Ikari for the police. Back at the office, Akiko shows Philip a thank you note from Dango and Chizuru inviting them to see their next dance performance, believing that he has changed from his experience. To Akiko's dismay, Philip throws out the note and expresses an intense desire to see Mount Fuji after reading about it in his books.
- Be Careful What You Wish For: Dango didn't think the Cockroach Dopant's site was actually real, he'd just wanted to vent in his anger at Chizuru. So when he finds out that people put on the site actually do die, he's reasonably horrified.
- Chandler's Law: When in doubt, write a message, tie it to a rock, and throw it through the small window in the Narumi Detective Agency. Also has the intended affect of startling everyone.
- Dance Battler: Double becomes this for the final fight with Cockroach, allowing him and Dango to counter his Super Speed with disorientation and retrieve the stolen Memories.
- Everything's Better with Spinning: Heaven's Tornado. Full stop.
- Ten Minutes in the Closet: Invoked when Philip runs a search for "methods of reconciliation", and gets the idea to do this for real...by using the RevolGarry.
- Wake-Up Call Boss: The Cockroach Dopant, who actually manages to be a threat due to his Super Speed enabling him to evade everything but LunaTrigger's shots and snatch Double's Gaia Memories.