Kengo begins to learn more of his father from Emoto and Gamou during his trip to Kyoto. Eventually, he learns that they are both Zodiarts and the full story behind his father's death and that the Horoscopes must be stopped from having all 12 switches. During the incident with the Gemini Zodiarts that followed, Gamou noticed a power emitting from Kengo. From the contents of Emoto's flash drive, Kengo learns of his true nature as the Core Child, a physical construct made of Cosmic Energy from within the Core Switch which the Presenters sent to OSTO to prove humanity's worth to contact them. However, only his adopted father Rokuro Utahoshi knew the truth with Kuniteru Emoto, who regretted his role, bringing Kengo to Earth.
He uses this newfound knowledge to awaken his powers to negate the 12 Horoscopes Switches, thwarting Gamou's plan to seek the Presenter. However, he becomes emotionless to make his next action less painful as he can now use the Fourze Driver. Kengo reveals his true nature to his friends and that he must leave Earth to present what he have learned to the Presenters' home world. However, Gentaro sees through Kengo's facade and convinces him that he is still a person while promising him that they would meet again. Unfortunately, refusing to leave him leave the Milky Way, Kengo's departure is interfered by Gamou assuming his Sagittarius Nova form to knock the youth down and destroy the Core Switch, causing Kengo's body to dissolve into particles of light. However, on the verge of death, Gamou uses the Aquarius Switch's power to repair the Core Switch and bring Kengo back to life. Kengo is named after Kamen Rider 1, also known as Takeshi Hongo. Yuki Jojima He is a second-year student and is Gentaro's childhood friend with a cheerful personality who cares deeply for her friends. As a child, Yuki heard a voice from the stars which influenced her with the desire to become an astronaut. Since then, Yuki became what she refers to as a "space otaku", called a "geek" by everyone else, and occasionally going to the JAXA building after school. She has supported Kengo in his activities in preparation for the Zodiarts' appearance. During her third-year, Yuki became the Kamen Rider Club's new president after Miu graduated and is capable of leading the club with her ingenuity though Miu's return as the club's chairwoman makes Yuki a figurehead leader. Yuki also has a plushy satellite toy she affectionately calls "Hayabusa", which seems have a different facial expressions depending on the situation. During the incident with the Gemini Zodiarts, an embodiment of her darkness who ruins her life, Yuki finds herself ceasing to be before Gentaro saves her. Yuki is named after Riderman. Miu Kazashiro Miu Kazashiro is a cocky third-year, later graduate, student who comes from an upper-class family. She is also the head cheerleader and has been elected the "Queen of the School" for having won two years in a row putting a lot of effort and hard work into getting where she is now, and has a large number of fans. Miu believes that she needs to know everything that occurs within the school grounds. She takes an immediate dislike to Gentaro and calls him trash when she first meets him. This mentality is later used against her by her sidekick Tamae Sakuma during this year's Queen Festival, as Tamae had secretly recorded Miu destroying her adoring public's gifts and have the video played in front of the entire student body. Humbled, and with Gentaro's help, Miu is reminded of her passion and returns to competing in the Festival despite the odds against her. Soon after, she accepts Gentaro's hand in friendship and manages to win the Queen Festival yet again, as well as the love of the student body in general with a speech.
Soon after, as her way to let Gentaro off the hook on the bet they made prior to the contest, Miu has him bring her to the Rabbit Hatch. Miu is made a member of the Club, much to Yuki's chagrin when Miu announces that she is the club president. She is capable to speak confidently even when a Zodiarts is terrorizing the place around her, and when she stops Yuki from revealing details about their club to save Kengo when he got trapped on the moon, never forgetting that their primary role is to stop the Zodiarts. While she keeps her elitist attitude, she also becomes genuinely more caring towards others, especially with her fellow members and would go to lengths for their sake, even if it means getting herself really dirty. Realizing that she would soon be graduating, she chooses Yuki to be the next president. After finding out about the Coma Zodiarts, she realizes not only has she made the right choice. Upsetting herself over this, she directs her fury at Shun who desperately attempts to ask her out to prom when she wants to ask Gentaro, instead. She gets her wish to dance with Gentaro due to Shun's insistence and realizes that though she is leaving the high school, she will always be a part of the Club. After graduating, she finds out that her college is close to AGHS so she can continue her Club activities as chairwoman. This effectively returns the leadership of the club to her, and thus rendering Yuki's appointment moot. In the end, Shun proposes to her but is soon enamored by a ring from a mysterious man. Miu is named after Kamen Rider V3, also known as Shiro Kazami. Kaizo Jingu Kaizo is known better by his nickname JK (pronounced "Jake"), is student who acts as an information broker to other students, but he only trades secrets for favors. However, he is known to be a coward. Before attending AGHS, JK had dreams of becoming a rock musician like his father since he was a child and formed a rock band with Tojiro Goto. However, while in middle school, JK was forced to give up on his dream when learning he couldn't sing. JK learned of Gentaro's identity as Fourze, agreeing to keep his mouth shut about it prior to talking Gentaro into protecting him from Fumihiro Nitta, a student he wronged by tricking him into being his bodyguard. Seeing the power of the Astroswitche, JK arranges the theft of the Elek Switch from Gentaro to teach him a lesson in trusting people, as well as to have him stick around in case Nitta comes for him again. However, once found out, JK is held captive by Nitta who allows him to call for help on the promise to release him if even one of his associates came to his aid. Though none came, Gentaro arrived to save JK despite his betrayal. The experience Gentaro learned from befriending someone like JK, to both the pros and cons of a person, allows him to assume Elek States.
After JK learns what friendship really means, he is made a member of the Club and uses his connections to aid the group in identifying Zodiarts' Switchers and their targets through his connections. When Miu and Shun graduate, JK is named the new pilot of the Powerdizer. While he proves to have a talent in piloting the heavy machine, his lack of experience and lasting stamina prevents him from piloting effectively. Luckily, as his college is near AGHS, Shun returns to the club to continue his role as the Powerdizer pilot, but mostly coaches JK in his new duties. He also incorporates his breakdancing skills whenever he pilots the Powerdizer. JK creates the alias of DJ Gene to set up an internet radio show as a means to live out his rock star dream, but the show becomes more popular than he expected. He is reunited with Tojiro Goto, but becomes conflicted between his loyalties to his old friend who is one of the Horoscopes and to his new friends. Goto urges JK to continue with the show, using his sonic powers as the Capricorn Zodiarts to make them even more popular. When JK discovers Goto's powers are brainwashing everyone in the school, but he doesn't want to be like his father who gave up on his dreams, so he keeps the show running and leaves the Kamen Rider Club. However, after seeing Gentaro stopping the Capricorn Zodiarts's music with his father's song, and being forgiven for his role, JK ends his broadcast and dream. JK is named after Kamen Rider X, also known as Keisuke Jin; "JK" are Jin's initials. JK's real name is also a play on Kamen Rider X being a "Kaizorg”. Shun Daimonji Shun Daimonji is a third-year, later graduate, student who is captain of the American Football team. His life has been planned out by his father, raised to believe that those under him are trash and how to play them to suit his needs. As he is consciously compelled not to shame his father, Shun distances himself from anything that he thinks could destroy his reputation, as he does with Miu when she fell from grace. Though he tries to reconcile with her, Shun is surprised when Miu breaks up with him and starts hanging out with Gentaro and his friends. He later gets forced into Mr. Satake's detention class for attacking one of his teammates who insulted his leadership abilities. Though he resolves to pass so he can return to his club activities, Shun's attempts to keep the Club members in the class eventually result with him being labeled as a delinquent by Mr. Satake as well. Gentaro's earnest effort in wanting to know him better eventually gets through to Shun, and he reveals in tears that he only wants to live up to his father's expectations, without being truly happy with who he is and what he has achieved. He confesses his envy towards the Club members, where the members stick together and have real fun.
Gentaro tells him that he should also do what he truly wants to and Shun accepts Gentaro as a friend and later battle alongside Gentaro, joining the Kamen Rider Club and providing his athletic prowess as the Powerdizer's official pilot. He is also very uncomfortable confronting his old attitude, especially when others are following his old example, and straightens out his teammates when they are acting like he used to, and out of guilt for pushing Miura over the edge, tries to bring Miura back to school by visiting him and apologize to him. When Shun and Miu are graduating, Shun insists on asking Miu to prom in very outlandish ways revealing that he has true feelings for her. However, he finds out the Miu wants to go to prom with Gentaro and becomes upset over this, even throwing a punch at Gentaro who went out of his way to get Miu to go with Shun to prom. While dancing with Miu, he realizes that the Kamen Rider Club are fighting to protect their prom and finds it hard to sit with that fact and just enjoy themselves, prompting him and Miu to leave the prom early to assist them. Afterwards, he insists that Gentaro dance with Miu like she wanted to, as Shun wants to send her off happy. After graduation, Shun finds out that both his and Miu's college is near AGHS, allowing both of them to continue their duties in the Club. Eventually, after the defeat of the Horoscopes, Shun attempts to ask Miu for her hand in marriage before the moment is ruined by the appearance of a mysterious Kamen Rider Wizard. Shun is named after Kamen Rider 2, also known as Hayato Ichimonji. Tomoko Nozama Tomoko Nozama is a goth girl who works at the Witches' Sacrifice occult store after school. Always seen with an iPad, Tomoko fixates over weird things, going so far as to delete the school's database because her bow is crooked when photos of her doing school activities were taken, "earning" her a place in Mr. Satake's detention class. Tomoko also has an acute sixth sense in sensing things others cannot, along with moving around undetected and giving people chills whenever she is around. She is capable of detecting energies of the Astroswitches. She is revealed to have knowledge of the urban legends of other Kamen Riders, playing an indirect role in the creation of the Kamen Rider Club. Since watching Yuki perform at the Queen Festival, seeing a kindred spirit in her, Tomoko begins to stalk her. Before she joins the Club, she is one of the few students to be aware of the existence of the Rabbit Hatch, but she does not know at the time that it is located on the Moon where she wishes to live on. Eventually, Tomoko joins a group of other goth students in a witches' coven called the Lunar Witches as its leader offers to make her dream of leaving the Earth to live on the Moon a reality. But she is devastated when she finds out that they are shams, which leads her to be approached by the Scorpion Zodiarts to receive a Zodiarts Switch. Believing she has nowhere to go except the Moon, and that her Zodiarts Switch may fulfill her dreams and become a new person, Gentaro takes her to the Rabbit Hatch to show her what the moon really looks like.
Although she is disappointed there is nothing but cold space, Tomoko is glad that she has finally gone to the Moon. She is accepted by the Kamen Rider Club members, she renounces the Lunar Witches and accepting Gentaro's hand in friendship while later, much to Kengo's chagrin, throws her yet-to-be activated Zodiarts Switch into the river near school. She becomes uncomfortable with occults after that. As a Kamen Rider Club member, Tomoko mainly uses her sixth sense to help out with investigations and detect things the others overlook. She starts to keep notes on Ryusei as she realizes strange things happen to him. Ryusei loses her trust at first for betraying the club and she tells him that he is not a true Kamen Rider. At the end, she sees Ryusei redeeming himself without the power of the Meteor Driver. Once the Aries Zodiarts is defeated, Ryusei regains her trust. At the end of Episode 40, Tomoko is banished to the Dark Nebula after she discovers that the Virgo Zodiarts is actually Professor Kuniteru Emoto but is soon brought back after revealing himself to the other club members. Tomoko is named after Kamen Rider Amazon, "Nozama" is "Amazon" backwards. Chuta Ohsugi Chuta Ohsugi is the second year geography teacher, and later third year homeroom teacher. He is disliked by many students, as it is part of his belief that teachers should not be friends with students. He is infatuated with Ms. Sonoda, even though she doesn't have any interest in him. Mr. Ohsugi also gets into arguments with Gentaro over him not wearing the school uniform, among many other things, and has since listed him as the top problematic student in the school. Ryusei also gets on Mr. Ohsugi's bad side by pointing out that Gentaro is within his rights in terms of the dress code not being strictly mandatory. He also happens to be very superstitious, reading the weekly horoscope and believing in curses. He likes to put up a strong front, only to shirk and cower later when things go haywire. He is also shown to be jealous of Hayami, as he is almost a complete opposite of what he is. He blames Gentaro and the others for Ms. Sonoda's health trouble. He arranges that he would be their homeroom teacher in their 3rd year and kept an eye on the three. His obsession with catching their misdeeds eventually leads him to discover the Rabbit Hatch and the existence of the KR Club. He finds it absurd that not only are the 3 problematic students are in the technically illegal club, second year students and even star alumni are in too. Even after hearing their reasons to have the club as such, Mr. Ohsugi still intends to disband the club as it has failed in following the rules, eventually escaping the Rabbit Hatch with a confiscated Net Switch to hand over to Principal Hayami. However, upon learning from Ran that some of the faculty are playing a role in the monster attacks, and after seeing the Club in action when they save him, Mr. Ohsugi gives the club his approval to be a legitimate school club. He becomes the group's academic adviser, stating that it his duty as a teacher to look out for his students and reconciling with the three he deems to be nothing but trouble. JK later tells Mr. Ohsugi everything about the identity of the Horoscopes and he is surprised to learn that Ms. Sonoda was the Scorpion Zodiarts. When the Leo Zodiarts tries to destroy the Rabbit Hatch, Mr. Ohsugi jumps into the fray and tries to stop the Zodiarts from harming his students, showing that he has become very close to the Kamen Rider Club.