天之川高中的新学期开始了，歌星·贤吾正全力调查学校周边的异常能量。转校生如月弦太郎的出现掀起了新的波澜，他的目标是“和全校师生成为好朋友”，当然也包括贤吾……

贤吾向弦太郎透露，他必须将被启动的Zodiarts开关关掉，才能真正的消灭Zodiarts。一同在校园里搜寻Zodiarts开关的持有者时，悠木为弦太郎讲述了更多贤吾的故事，以及他手中Fourze驱动器和天文开关的来源

一年一度的女王选举即将来临, 弦太郎与风城美羽之间也再度出现摩擦。两人建立赌约，要想美羽成为弦太郎的朋友，除非本次选举中有人能夺走美羽的女王之位。弦太郎多次寻求帮助无果后，只得求助于悠木，让她参加选举，并在才艺比拼中战胜未尝一败的美羽。

在女王选举的过程中，弦太郎逐渐了解了美羽的想法，转而决定帮助美羽重夺女王桂冠。同时作为Fourze，他也要在变色龙Zodiarts的手中救出美羽

美羽强烈自荐加入了假面骑士部，JK对弦太郎大献殷勤。与此同时独角兽Zodiaets盯上了JK，弦太郎在战斗中使用了新的天文开关——10号电力开关，却无法控制其能量。

弦太郎发现JK只是在利用自己以从Zodiaets的手中保护他，并且还偷走了自己的电力开关。尽管了解了JK是个欺诈师，但弦太郎还是决定用友情的力量来改变他。

由于在对抗Zodiaets的过程中翘课过多，贤吾、悠木和弦太郎被强制参加周日的特别补习课程。大文字隼也出现在了周日特别补习课堂上，他对假面骑士部的厌恶不断增长，更因美羽也参与其中而更加愤恨。所有人都在补习中时，只能依靠美羽和JK来维持局面……

弦太郎等人继续追踪猎犬座Zodiarts，天蝎座Zordiarts的出现令他们陷入苦战，屡次缺席也令他们的补习惩罚再度升级。在美羽受伤之后，隼的内心受到了动摇，终于在弦太郎的努力下，吐露出了他内心的想法。隼下定了决心，他的人际交往和学园生活，将从这里开始改变。

野座间友子突然向假面骑士部的各位宣言：世界末日将要来临，而她将要成为月之魔女。当三名魔女带着友子在学校中接连引发超自然现象时，假面骑士部必须查明，这究竟真的是魔法，还是暗藏了Zodiarts的力量。

魔女力量的真相终于被揭开，而魔女结社向友子抛出了橄榄枝。是按下Zodiaets开关并利用其力量实现自己的梦想，还是帮助假面骑士部的各位消灭正在大闹学校的Zodiarts，友子最终的决定是什么？

Yuuki is targeted by a Zodiarts who is obsessed with her. Meanwhile, the locker which attaches the Rabbit Hatch to the school goes missing leaving Kengo trapped on the moon.

Gentaro and the others decide to bring back those students who were Zodiarts to the school, starting with Toshiya Miura.

To save Miura from using a Zodiarts Switch again Gentaro must go up against one of the Horoscopes, Scorpian, a commander Zodiarts.

Yuuki is invited to join the Glee Club for a performance for the Kindergarten Class, however, her singing disrupts a fellow student in possession of a Zodiarts Switch.

The Perseus Zodiarts seems to be too powerful for Fourze to stop on his own, however, the appearance of the new Kamen Rider Meteor may change this battles ending...

After Kengo reaches a dead end in finding out the identity of the mysterious new Rider, Sonoda-sensei introduces new transfer student, Ryuusei Sakuta.

Ryuusei tries to gain membership to the Kamen Rider Club to further his own agenda but whilst most of the Club is fine with a new member, Gentaro is against Ryuusei joining...

Kengo has a fight with Gentaro due to his decision to let Ryusei for adjusting the Astroswitch (the reason of fight actually because trying to complete the imperfect Magnets Switch)

Gentaro and Kengo must find a way to overcome their rift before a powerful Zodiarts defeats both Fourze and Meteor.

With Sonoda still absent from the school Gentaro's class gets a new homeroom teacher who is far more interested in Kickboxing than teaching.

Gentaro and the others are convinced that their new Homeroom Teacher is the Zodiarts that is currently rampaging, however, Ryusei figures out that the culprit is not their teacher.

Gentaro and friends hear about a new hero from their classmate Norio Eguchi, who identifies the hero as Cygnus and also happens to be a member of the Ugly Duckling Society, a fan club dedicated to Cygnus. However, this new hero is not as good as he seems...

The gang must race to find out who the Switcher is- before the new 'hero' wipes out Fourze and Meteor to become the sole hero in the city...

Miu and Shun are due to graduate- however, it seems like it might not be smooth sailing as previous Zodiarts return.

Gentaro and the others protect the Prom for their friends who are graduating, while, Miu and Shun deal with the fact that they won't be part of the Kamen Rider Club anymore as they are going to college.

During Spring Break the gang decide to try and make the most of what should be a Zodiarts free time, however, Kijima tries to recruit Ryuusei to his side whilst playing a deadly game with students. And those who don't win are placed into permanent comas.

The Cancer Zodiarts threatens the members of the Kamen Rider Club now that he has attained the Supernova ability. While he still cannot transform, Ryusei discovers that Jiro's condition has taken a turn for the worse.

Gentaro and his friends enter the third-year class headed by Mr. Ohsugi, and Gentaro tries to befriend new first-year students Haru and Ran. However, Haru is given a Zodiarts Switch by the Libra Zodiarts.

Gentaro and the Kamen Rider Club must figure out how to deal with Haru as the Musca Zodiarts and Mr. Ohsugi's discovery of the Rabbit Hatch, along with the latter's confiscation of the 38th Astroswitch.

After the 39th and 40th Astroswitches are developed, Amanogawa and Subaruboshi High Schools hold a test transfer of some of AGHS's students to SBHS, which causes problems when the Aries Zodiarts makes itself known to the AGHS students...

After Gentaro's death at Ryusei's hands, Kengo does not know how to resurrect him as the Aries Zodiarts takes the other Kamen Rider Club members captive. Elsewhere, having betrayed Tachibana, Ryusei is able to talk to the revived Jiro.

The third-year class goes on a field trip to Kyoto where they believe they will be free from the Zodiarts for once, but are ambushed by the Libra and Leo Zodiarts. While there, Kengo meets one of his father's old friends. Meanwhile, a enamored girl is determined to snag Gentaro's heart, and poor Yuki is forced to help...

The Kamen Rider Club must work to stop the Libra and Leo Zodiarts from destroying the last two altars in Kyoto to destroy the city with The Hole's Cosmic Energy. In the process, Kengo finally learns the circumstances of his father's death.

With The Hole gone from Kyoto, AGHS is the focus of its Cosmic Energy and the other Horoscopes will soon be found. An internet radio show started up by the mysterious DJ Gene, soon discovered to be none other than JK, grabs the school by storm. He starts up a musical contest, which grabs the attention of the Kamen Rider Club and a fellow student who turns out to be the Capricorn Zodiarts.

Kamen Rider Fourze must defeat both the Capricorn Zodiarts and the Zodiarts' song that has enraptured the school, but with Cosmicstates out of commission after Gentaro's bond with JK is severed, can he find a way to rebond?

Gentaro, Yuki, Kengo, Tomoko, Ryusei, the student council president Sugiura, the former Pyxis Zodiarts Hiroki Makise, and transfer student Erin Suda are chosen for an astronaut test in a closed environment and endurance test, but Kengo's weak constitution and the arrival of the Aquarius Zodiarts cause trouble for the group.

Yuki passes under suspicious means, while Gentaro tries to convince Erin to not follow the path the Horoscopes want of her, as well as give up her hatred for Yuki.

Acting student council president Sugiura institutes a new set of rules that all students have to follow, severely limiting the freedoms the school initially allowed them.

As the Taurus Zodiarts, Sugiura continues to stifle everyone's creativity, but Ryusei (as Meteor) challenges to a game of golf to get everything back to the way it was, while Gentaro and Yuki try to find out why Yuta had changed.

The Virgo Zodiarts begins attacking other members of the Kamen Rider Club, scaring them away from the club, blocking Fourze from accessing Cosmicstates. However, Tachibana arrives on Earth to show Gentaro a way to fight with other abilities at his disposal.

With most of the Kamen Rider Club taken out of commission the Virgo Zodiarts, Gentaro and Kengo are on their own in their fight against Virgo after Meteor is sent to the Dark Nebula and the others distance themselves from the Club. And things get worse when the new powerful member of the Horoscopes, Sagittarius, appears...

Yuki starts acting stranger than usual, and when strange incidents gets traced back to Yuki, and Yuki somehow transforming into the Gemini Zodiarts, Gentaro begins to suspect something is up.

The Kamen Rider Club work to save Yuki from ceasing to exist as Dark Yuki begins to take her place as the real Yuki.

While celebrating Kengo's birthday, the Horoscopes have located their final member, Pisces, in Ran Kuroki, who has been given the chance to study abroad in America. But after Leo attacks, Hayami gathers the Kamen Rider Club to tell them the truth of what has been happening and prevent Ran from becoming the final Horoscopes.

Ran refuses to give her Pisces Zodiarts Switch that will finalize Gamou's plans, so he sends Tatsugami to take her Switch. Elsewhere, Kengo discovers a secret from the USB drive he found in the late Emoto's office.

With Gamou's scheme with all twelve Horoscopes Switches thwarted, Kengo reveals the truth of his origins to the Kamen Rider Club and his eventually parting with his friends. However, the Horoscopes attack the Rabbit Hutch to kill Kengo, getting the Kamen Riders to desperately fight back to protect their friend, who must go back to the Presenters.

With Kengo's death at the hands of Sagittarius Nova and the destruction of the Rabbit Hatch, a distraught Kamen Rider Club reads the final letter from the Core Child written before his death. A resolved duo of Riders must face the Horoscopes one last time to avenge their fallen friend and stop the Day of Awakening for good.