Popular national talent Nemu has been kidnapped by a criminal organization! Just when everyone is about to despair, the strongest agent appears! "Code number: Seven, carry out the mission." Seven fights with gusto! He rescues Nemu, and the two of them get along well... Or so Mozu, an ordinary, good-natured young man, dreams. Whenever he tries to help someone, he somehow ends up suffering nightmarish misfortune. But the only place where he can become his ideal self is the dream world. However, a nightmare monster, Nightmare, attacks this dream world! Mozu takes action to stop those who are invading his dreams and trying to erode reality as well. He may be ordinary in reality, but he is the strongest in dreams! When Mozu believes in his dreams, Kamen Rider Zeztz awakens.

For some reason, Moko (Ryutaro Imai) has become a fugitive in his dreams. When he encounters the bomber Nightmare, he transforms into Zetts, but the bomber escapes. One night, Moko is suddenly summoned by Zero (voice: Jiei Kabira) and given the command to "infiltrate other people's dreams and prevent Nightmare's nightmares from happening." This means that he must stop the bomber... And so begins Moko's mission to protect his "dream owner"!

The dream owner this time is Detective Fujimi. But does Fujimi really want the bombings to continue? Deep in his psyche lies a locked door of the mind — and if this final door opens, nightmares may pour into reality! Even being all-powerful in dreams, Makoto (Baku) outside of them is just an ordinary young man. Now, as agent ZETTZ, he faces a real confrontation. The true fight begins now.

Moko infiltrates a wedding rehearsal. The groom is the heir to a wealthy family, and the bride's father is a powerful politician. Could the assassin be from a rival faction, or...? In order to prevent a tragedy like the bomber from ever happening again, failure in the mission is unacceptable. With Z Gear and a new Capsule "Wing" in hand, can Moko become a true agent? Fly towards your dreams, Z!

Why is the bride Miyuki the dreamer? Baku, who continues to gather information in the real world, comes in contact with Miyuki standing in front of a large tree in the park. He learns that Miyuki has a memory of the tree that could change her life. In the dream world, Baku finds Miyuki's Mind's Door and sees an unexpected scene behind the door. The Crow Nightmare appears again and attacks Miyuki and everyone else!

Tonight's mission is to escape from a giant prison. And the captured targets are... Nemu's parents!? The worldview, the characters, the nightmare. In a dream where everything is shrouded in mystery, can Mo reach the subconscious of the dreamer? His trump cards are the "Z Camera" and the "Machinery" capsule. And finally, Nox, the mysterious man who wanders through dreams, makes his move!

The inescapable giant prison was Prison Nightmare itself! The Nightmare is a manifestation of the dreamer's deep psyche. Within it lay the true reason why President Bijogi locked up 'Nemu' in the prison. It was a certain secret hidden within the nationally popular talent— Would destroying the nightmare created to escape the suffering of reality truly save the dreamer? The "Projection" Capsum reflects all the truth.

Destroy the biological weapon. Royal Jōkin is a century-old restaurant. It continues to preserve its traditional flavors and is so famous that its food is even served at international conferences. However, the restaurant is now under threat from a biological weapon. One by one, chefs are falling. Who is the culprit, and what can be done to counter this invisible enemy? This is where Capsule Recovery comes in, Seven.

What kind of nightmare does Chef Sannou desire? Inspired by what Shiomi and the others said in the real world, Baku discovers Sannou's third "door to the heart" in his dream. He peers inside...! While Fujimi and the others rush to thwart the summit, Baku transforms into Zetts and clashes with Poison Nightmare. But then, Nox appears again...!?

Baku, tasked with the mission "Recover State Secrets," infiltrates the home of art collector Atsumi in a dream. A theft occurs involving a famous painting from Atsumi's collection, and Baku suspects state secrets are hidden within that painting. However, as Baku pursues the culprit, Nox appears and warns him, "Knowing too much will destroy you." The next instant, Baku is struck by a blow from Nox's weapon...!?

The masterpiece stolen in his dream has been corrupted by Nightmare. If things continue as they are, the state secrets hidden in the painting will never be released... Baku is dejected, but Zero scolds him in an unusually harsh tone. Baku transforms into Zetts again in his dream. Just as he obtains the Wonder Capsule to protect Atsumi from Mold Nightmare...!?