Using the Sengoku Driver which cuts the Lock Seed and opening a small hole to this other world, the user can transform to one of these: Kamen Rider Gaim, who uses the "Orange Lock Seed" and the "Pineapple Lock Seed" to summon "Orange Arms" and "Pineapple Arms", Baron, a Western Armor motif and uses the Banana theme; the Chinese Armor motif Ryugen who uses Grapes, Griton who uses Melon, and Zangetsu who uses Coconut.

Kamen Rider Gaim is Kota Sakuraba, the 2nd dancer for "Team Gaim" but eventually stopped playing the game and left to look for a job, and protect his lonely sister. He's a nice guy, and "protecting people" is his very reason in fighting. He accidentally found the Sengoku Driver.

Kamen Rider Balon is Kaito Kumon, the leader of "Team Baron", Team Gaim's rival. Growing up as a poor guy, he always believed that the weak warriors are exploited. He is now hungry for power.

Kamen Rider Ryugen is Mitsuzane Kuwashima, a member of Team Gaim and Kota sees him as his younger brother. Though he kept this as a secret, in reality, he is the son of the leader of the Yggdrasil Corporation and attends an elite high school. He wants to live freely won't accept the path established for him.

An aspiring pro dancer and a childhood friend of Kota, Mai Takatsukasa takes care of all of the members of Team Gaim. Though he thinks of Kota as her rival, she actually adores him.

Kamen Rider Zangetsu is Takatora Kureshima, Mitsuzane's older brother and holds a high position at the Yggdrasil Corporation. Although he is a ruthless realist, he still loves his family.

Other members of Team Gaim are: Chucky the top-level dancer, the easy-going and not so good dancer Rika, and the team's mood maker, Rat. Meanwhile, other members of Team Baron are the loyal and trustworthy Zach, who's the 2nd-in-command, and Peko who plots to win at Inbess Games in a makeshift fashion.

Supporting cast includes Kota's sister Akira Kazuraba who works as an office worker at a subsidiary of Yggdrasil, and Kiyojiro Bando, the owner of a fruit parlor "Droopers". Team Gaim are regular customers at Kiyojiro's Droopers.

As always, there are mysterious characters in the show. Sid, the Lock Dealer, who sells Lock Seeds to young guys to facilitate their Inbess Games. Definitely having a motive behind all of this, no one really knows where he gets them. Lastly, there's pirate radio DJ Sagara who incites the excitement in joining Inbess Games, and making it fashionable.