While figuring out how best to use his newly acquired powers, Kota witnesses his rival, Kaito Kumon's, summoned Inves go on a rampage and becomes determined to protect people as the samurai-themed Kamen Rider Gaim (who utilized The Orange Lockseed).
In the middle of the series, Kota continues his fight towards the corrupt Yggdrasil Corporation after discovering the company's shady attempts at covering up the Inves attacks with the Beat Riders being scapegoated as a result.
With Kota emerges as the victor, he ascends to the title of Man of the Beginning, removing Helheim's influence on Earth to another planet as their new ruler alongside Mai.
As a result, Kaito grew up in a poor household, his father became abusive towards him and his mother, and both of his parents eventually committed suicide, leading to the orphaned Kumon falling into the Takatsukasa family's care.
However, his desire to protect Kota and their mutual friend Mai Takatsukasa from the truth and discovery of what happened to Team Gaim member Yuya Sumii leads Mitsuzane to help Takatora conceal information on the Helheim Forest instead.
Eventually in the middle of the series, Mitsuzane went insane from the influences of both the Yggdrasil workers and the Overlords, secretly opposing Kota and the Armored Riders from the shadows before his treachery is made public.
However, her attempt at trying to alter the past gets her trapped in an alternate timeline, necessitating for Kota to win the fight against Kaito to bring her back and earning the Forbidden Fruit to himself.
A realist who is willing to commit morally dubious acts for the greater good of humanity, he has a bad habit of trusting the dishonest and dearly loves his younger brother, desiring for him to do well in school so he can join the family business one day.
Through his encounter with Kota and the Overlord Inves, Takatora is about to consider a safer alternative for humankind's survival but was ousted from Yggdrasil once he becomes a liable to Ryoma's plans.
Kota heals him after ascending to role of the Man of the Beginning, with Takatora keeping his promise to reconcile with Mitsuzane and participating in the rebuilding of Zawame City.
He initially refuses to join Team Baron's alliance until he is defeated by the group's leader Kaito Kumon's summoned Inves and Kota Kazuraba as Armored Rider Gaim, both of which convince Hase to do so.
In response, Jonouchi joins forces with Ryoji Hase of Team Raid Wild and obtains the means to transform into the Greek soldier-themed Kamen Rider Gridon (仮面ライダーグリドン, Kamen Raidā Guridon), but quickly becomes known as the weakest of the Armored Riders due to his lack of combat prowess and saddled with what he considers the worst name out of all them as it is simply an anagram of the Japanese word for "acorn".
The Yggdrasill Corporation Company Ltd. (ユグドラシルコーポレーション, Yugudorashiru Kōporēshon) is a powerful multinational conglomerate and research organization largely dedicated to stopping the Helheim Forest from overrunning the Earth.
Yggdrasil also establishes the Inves Games and the Armored Riders to further their research and draw attention away from it as well as create weapons to repel Helheim's inhabitants.
Lock Dealer Sid (錠前ディーラー シド, Jōmae Dīrā Shido) is one of Takatora Kureshima's subordinates who aids him by selling Lockseeds and Sengoku Drivers to the Beat Riders for the Inves Games.
Amidst the Inves' invasion, Drupers remains open and serves as a secondary base for the Armored Riders until the Japanese Self-Defense Forces arrive and close down the store to evacuate Zawame.
The Inves (インベス, Inbesu), the name of which was derived from the term "invasive species", are monsters who hail from the alternate reality of the Helheim Forest (ヘルヘイムの森, Heruheimu no Mori).
Dēmushu (デェムシュ) is a hot-tempered, anger-prone brute clad in crimson (真紅, shinku) armor who enjoys fighting, seeing humans as weak "dyoburyo" (デョブリョ),[f] that deserve death by someone as strong as himself.
Redyue (レデュエ) is a feminine, sinister, and sadistic Overlord clad in jade (翡翠, hisui) armor who uses others as her personal play things until she discards them when they are of no more use to her.
Roshuo (ロシュオ) is the leader of the Overlords clad in chalk (白亜, hakua) armor who normally rests deep within the ruins of his former civilization and believes humans are no different from the Femushinmu.
However, as those blessed by the forest slaughter those unable to fight back, Roshuo learned too late that his wish caused a conflict that destroyed the Femushinmu civilization, with his queen among the casualties.
Years prior, he built a childcare facility for Zawame City's orphans, such as Tōka Akatsuki and Ryoma Sengoku, but secretly used the children to either conduct Helheim-related experiments on or select to work for Yggdrasil.
Shapool (シャプール, Shapūru) is the heir of a foreign country who physically resembles Kaito Kumon and first appears in the V-Cinema Gaim Gaiden: Kamen Rider Baron.
In the Kamen Rider Gaim tie-in novel, Shapool takes over his adopted father's foundation after the latter was arrested for supplying the Black Linden cult with Sengoku Drivers, forcing the young man to work feverishly to get the organization back on the right track.
Alfred (アルフレッド, Arufureddo) is Shapool's family's strict butler who appears exclusively in the V-Cinema Gaim Gaiden: Kamen Rider Baron.
Unbeknownst to Alfred however, Sengoku was secretly using him to test the Dragon Fruits Energy Lockseed, which gradually turns the butler into the ox-like Overlord Tyrant (タイラント, Tairanto).
Kudo was trapped in a state of limbo until he received the Zakuro Lockseed from DJ Sagara and uses his newfound abilities to establish the Black Linden (黒の菩提樹, Kuro no Bodaiju) cult and lead them as their messiah claimant while using his brainwashed followers as expendable suicide bombers.
Following Shura's death, Kudo instigates chaos in Zawame by creating Bodhi Tree-like roots that turn its citizens into mindless slaves before converting them into Overlord Inves.
In addition, Kudo can also assume monstrous forms, such as Lotus Position False God Saver (蓮華座偽神セイヴァー, Renge-za Gishin Seivā), a giant snake monster, and a Skeletal Dinosaur (骸骨恐竜, Gaikotsu Kyōryū).
After its branch of the Yggdrasill Corporation activated the Scalar System, the Torkia Republic was destroyed and reduced to an underground city in which its low-ranking citizens were forced to fight against one another to survive while its noble residents live on the surface and benefit from the conflict as a form of entertainment.