- Title: Kamen Rider Chou Den-O Trilogy Episode Yellow
- Alternative Title: 仮面ライダー 超・電王トリロジーEPISODE YELLOW お宝DEエンド・パイレーツ Kamen Raidā Chō Den'ō Torirojī Episōdo Ierō Otakara DE Endo Pairētsu
- Number of Episode: 1
- More Info: https://en.wikipedia.org/wiki/Kamen_Rider_%C3%97_Kamen_Rider_%C3%97_Kamen_Rider_The_Movie:_Cho-Den-O_Trilogy
- Summary: At night in Tokyo, a man jumps from building to building, leaving sparkly sand as he moves. Momotaros and the other Tarōs pursue him, with Momotaros thinking he met him before as the figure easily dispatches his pursuers. When Ryotaro arrives, the Spider Imagin possessing the man emerges, having completed the contract with the boy's appearance. Ryotaro uses a Rider Ticket on the man, chasing the Imagin to November 22, 2008, with Den-O Sword Form quickly taking the Spider Imagin out. As Momotaros and the others look around for the Rider Pass he tossed aside while performing the finishing attack, they see the possessed man from before holding it, revealing that he used the Spider Imagin to possess him so he could hijack the DenLiner as Momotaros remembers who this man is: "that robber rider" Daiki Kaito. Stranding Ryotaro and the Tarōs in 2008, Daiki holds the Owner and Naomi at gunpoint as the Owner reveals his plans to steal time failed as the DenLiner can only go to the date on the ticket as it was a strong memory that keeps it from fading. Realizing that there is a treasure nearby, Daiki runs off to find it.
Seeing the DenLiner over the distance, Ryotaro and the Tarōs chase after it until Ryotaro sees Daiki running off in another direction. He finds Daiki confronting his past self, shooting him dead to Ryotaro's shock. However, past Daiki's wound heals as he runs off with Daiki shooting him more. Soon as the Tarōs arrive, a man suddenly appears from another point in time with a golden revolver trained on Daiki, Officer Reiji Kurosaki. He has come to arrest Daiki for threatening to cause a time paradox before transforming into Kamen Rider G Den-O as Daiki responds by becoming Kamen Rider Diend. Ryotaro and the Taros watch G Den-O as he overwhelms Diend with his advance arsenal and the intelligence of the artificial Imagin Eve before arresting him. However, with the Time Police taking over, G Den-O arrests the Tarōs on the charge of altering time and deporting Ryotaro to his time. Only Urataros escapes long enough to witness past Daiki stealing a briefcase from the Kurosaki estate, pushing aside a young boy who got in his way, before G Den-O finds him. Back in the present time, as Issē and Ozaki look at the drawing Ryotaro made of their family, Ryotaro talks to Kohana of what Urataros told him prior to his arrest. Overhearing their talk, Ozaki remembers a theft occurred at the Kurosaki estate on that date: someone broke in and stole the family's golden gun. But it leaves the question to why Daiki went to that moment of his past.
At the Time Police's jail, the Imagin try to talk their way out as Daiki complains about their nosy racket as Urataros reveals he know about his robbery. By then, Kurosaki arrives with two guards, ignoring the Taros while telling him the will be judged while phrasing what Urataros heard Daiki tell a young boy in the past. By then, the Owner appears to bail the Taros before being arrested as an accomplice with the DenLiner now Time Police property as Daiki manages to grab one of guards, faking a wish to give up his life of crime to sneak the keys off the man and using them to frees himself, throwing the keys to the Imagin a bit out of reach. After failed attempts to get the keys, they see Ryotaro and Kohana have been arrested as well, and put into the cell next to the Tarōs who are still trying to reach the keys. Ryotaro beckons for Momotaros to come closer, which Momotaros realizes what is being said as he possesses the boy, beating the guards with Kohana as she lets everyone free. Ryotaro says they still have to get to the DenLiner, and the Owner gives him an Infinity Ticket to solve the mystery while he has a meeting with the Station Master.
On the DenLiner, Naomi arrives to tell Kurosaki that Daiki has escaped. However, Kurosaki senses something off and aims his damaged golden gun at "Naomi," revealing her to be Daiki. Daiki then takes of his Naomi disguise as he is forced off the DenLiner at gun point and clearance to execute. Daiki attempts to distract Kurosaki by pointing that Ryotaro and company are behind him as the DenLiner crew takes control of the DenLiner once more and return to November 22, 2008. Daiki has used the Diendriver to latch onto the back of the DenLiner, traveling with them as Eve deems them all for execution. Diend manages to get to the DenLiner's cockpit and holds Den-O at gunpoint, forced to explain that the purpose of his time trip was to undo the chain of events that left the gun damaged while Daiki was distracted by several letters hidden in the box so he can steal it in mint condition. Though the others refuse to help, Ryotaro decides to help Daiki with Urataros backing it up. Arriving at November 22, 2008, the group is ambushed by G Den-O as Den-O holds him off in his Ax and Gun Forms before Momotaros takes over the fight.
With Urataros possessing him to save him, Daiki transforms into Diend and uses the UraRod to deflect bullets back before using the Invisible Attack Ride Card to catch G Den-O off guard. By them, Daiki manages to make it to where his past self is before the gun is damaged, though Kurosaki appears. Before Daiki can get to his Diendriver once more, Kurosaki shoots him with the golden gun. The bullet goes through Daiki and hits the case the past Daiki is carrying, knocking it out of his hands, sending the papers within flying as Daiki gets the golden gun. Enraged that he was used, losing his golden gun as time has been altered so that it was never damaged and possessed by Daiki, Kurosaki stopped when he noticed the letters from the box. Daiki and Kohana reveal the letters to all to be from his mother, with the latter revealing to Kurosaki that his mother did loved him and wishes to see him. Though Kurosaki feels he cannot let go of his hate, Daiki tells him that the letters should be his treasure. Disappointed that Kurosaki refuses to deliver final judgment, Eve takes matters into his own hands and becomes G Den-O to purge the Earth of all illogical life.
Everyone escapes from G Den-O as Daiki runs into his past self and asks for his aid against G Den-O. Both transform and past Diend steals the golden gun as he falls back. Den-O arrives to support Diend with the others. But the five are outmatched by G Den-O until Den-O assumes Climax Form as Kurosaki arrives with Diend saving him from a stray shot. Kurosaki thanks Diend for opening his eyes as he gives him a K-Touch which he soon uses to become Diend Complete Form. He then uses the Attack Ride Gekijouban Card to summon Kamen Riders G4, Ryuga, Orga, Glaive, Kabuki, Caucasus, Arc, and Skull, and as a group with Den-O Climax Form, destroy Kamen Rider G Den-O. In the end, before entering the Hikari Photo Studio, Daiki thanks Ryotaro and Kohana for their help as Kurosaki goes to visit his mother at a flower shop, wanting to talk to her as he learns that she truly cared for him. On the DenLiner, as the others are perplexed as the Owner arrives with the Station Master as they start a contest where they are flicking balls of fried rice at plates at distances with the Owner using the spoons from Episode Blue used as a golf club while they measure the distance with the tape from Episode Red. Soon after, Naomi serves everyone coffee as Ryotaro's regular mug is missing, realizing that Daiki must have taken it. Back at the photo studio, though he believes that would be their last meeting, Daiki would never forget Kamen Rider Den-O.