Kamen Rider Series - Season 31

Novelist and bookstore owner Touma Kamiyama suffers a recurring dream about a place called Wonder World invading the real world and his inability to save a mysterious young girl 15 years prior. His dreams become reality when he is dragged into a war to decide the fate of both worlds, so he takes matters into his own hands when he obtains the means to transform into Kamen Rider Saber.

Touma is visited by a man from the Sword of Logos, Rintaro Shindo, who has come to relieve him of his SworDriver and Brave Dragon Wonder Ride Book. When Touma refuses to give them up, Rintaro takes him to his organization's headquarters to debrief him on the conflict he has become involved in. Touma now faces the choice of whether to use his power as Kamen Rider Saber to save people and the world, or stay out of it.

Touma meets two other members of the Sword of Logos. One is Kento Fukamiya, his childhood friend, and the other is Ryo Ogami, a great swordsman who divides his time between fighting and raising his son, Sora.

Despite Ryo defeating the Hanzaki Megid, the place it attacked did not return to normal and Sora is still missing. In response, Touma and the other members of the Sword of Logos look for a way to rescue him.

Touma and his friends must face Kamen Rider Calibur, a former member of the Sword of Logos who defected to the Megid's side. Meanwhile, Touma realizes that Kento is disturbed by the enemy's appearance and learns the connection between them.

Another member of the Sword of Logos, Ren Akamichi, visits Touma's bookstore seeking Kento's recognition. When he learns of Kento and Touma's friendship however, the young ninja develops a rivalry with the latter. Meanwhile, Megid commanders Storius, Legiel, and Zooous make their move against the Sword of Logos.

Touma and Kento depart to look for the mythical land of Avalon so the former can unseal his sword, but Calibur stands in their way, intending to claim the secret power located there for himself.

After claiming the King of Arthur Wonder Ride Book and unsealing his sword, Touma begins to doubt if he can master the former's power. After Ryo is turned into stone while protecting him however, he comes with an idea to rescue him with help from his friends.

After his recent feats, Touma is recognized by the others as a full-fledged member of the Sword of Logos, but when the Megids prepare multiple Alter Books for their next plan, Tetsuo Daishinji, the order's mechanic, joins the fray as Kamen Rider Slash after repairing his own weapon.

Calibur steals some Wonder Ride Books from the Sword of Logos to complete his plan. While fighting to get them back, Touma and his companions discover his true identity.

Touma and the others are shocked to discover that Calibur is Daichi Kamijo, the previous Kamen Rider Saber while Kento is in distress over not knowing his father's whereabouts. Meanwhile, the Megids strike again and Daichi appears with a new power that makes him a bigger threat

After Rintaro is deeply wounded while protecting him from Daichi, Kento becomes determined to strike the enemy down not only for his sake, but also to avenge his father. Meanwhile, Touma and the others attempt to stop the Megids' plans.

Touma regains all his lost memories and realizes Daichi and the Megids' true objective, which is to recreate the same cataclysmic events of 15 years ago. Determined to stop them and avenge Kento, he obtains a new power.

While Touma was able to defeat Calibur and foil his plot, Kento has mysteriously disappeared. As the Megids continue to move forward with their own plans, the swordsmen head into battle against them with Kento's sword and Wonder Ride Books as well as a new power for Rintaro.

Touma dives into a portal opened by the pillars of light to stop Calibur while the other swordsmen look for a way to close it despite being warned by the Megids that Touma will not be able to return if they do so.

After defeating Calibur and averting the latest crisis, Touma prepares to celebrate the new year with his friends, when Sword of Logos member Reika Shindai approaches him with unknown intentions.

Storious creates the Grimoire Wonder Ride Book using Legeiel, Zooous, Isaac, Tassel, and Charybdis' powers along with the Tome of Omniscience. Moreover, he reanimates the Sword of Logos' Four Sages. Meanwhile, despite struggling to stop Wonder World's collapse, Touma and his fellow swordsmen must face Storious if they hope to save the world.

As Storious' plan progresses and Wonder World and Earth collapse, the swordsmen are unexpectedly joined by Sophia as the latest Calibur as well as Luna and Mei. With their forces bolstered, the swordsmen face Storious and his army.

One by one, the swordsmen fall for one reason or another as Storious overwhelms them. Touma attempts to face him alone, but learns a horrible truth regarding the Almighty Book. Meanwhile, as Wonder World vanishes and Earth collapses, a vanishing Mei reaches a decision as she attempts to reach a similarly vanishing Luna.

The source of the swordsmen's power and the source of stories, the Wonder World, disappears, and as the stories vanish from the world so does the world itself. Yuri advances onwards while faced with his own disappearance, as Luna races to see Touma before it's all over. Rintaro and Ren force themselves forward with the last fragments of their strength. Just then, their Wonder Ride Books lose their power and the Wonder World completely disappears. When that world vanishes, so does Touma. Everything is proceeding as it has been written within the pages of the Almighty Tome. In the midst of the world's greatest crisis, "Do you know a story you can never forget?"