|This article is about a/an episode in Kamen Rider Gaim.|
Birth! The Third Rider is Grapes! (誕生！3人目のぶどうライダー！ Tanjō! Sanninme no Budō Raidā!) is the fourth episode of Kamen Rider Gaim. It features the debut of Mitsuzane Kureshima's first transformation into Kamen Rider Ryugen.
Kouta and Kaito work together to try to find Yuya, but they instead face off against an even more terrible enemy.
Finding themselves in Helhiem Forest, Kouta reveals to Kaito that he has been in the dimension before. With the knowledge that are unripen Lockseeds in the area, Kaito wanders off to get some before returning to his world. Kouta decides to use this time to find Yuya, but instead finds some researchers before getting into a fight with a terrible enemy: A white Armored Rider.
Defeating a Shika Inves, Armored Rider Gaim is overpowered by the white Armored Rider named Kamen Rider Zangetsu, convincing him that his Sengoku Driver was forbidden. The next day, after returning from Helhiem Forest with high class Lockseeds as bargaining chips, Kaito calls Team Raid Wild's Ryoji Hase and Team Invitto's Hideyasu Jonouchi to set up an alliance among their groups to take out Team Gaim.
At that time, Mai and Mitsuzane are called by Akira to check up on Kouta who tells them of his near death experience with the mysterious Armored Rider and that he is giving up being an Armored Rider. Taking the Sengoku Driver to Team Gaim's garage, Mai tells Mitsuzane of her experience in Helhiem Forest and that they can not rely on Kouta anymore for his own good.
But confident that Kouta will return, Mitsuzane meets up with Sid the following day and uses his status as a member of the Kureshima family to convince the dealer to provide him with a Sengoku Driver. When Team Invitto arrives to Team Gaim's stage with an Ichigo Lockseed, understanding the protecting others means risking his own well being, Mitsuzane reveals his new Sengoku Driver and uses the Budou Lockseed to transform into an Armored Rider.
- Kouta Kazuraba (葛葉 紘汰 Kazuraba Kōta): Gaku Sano (佐野 岳 Sano Gaku)
- Kaito Kumon (駆紋 戒斗 Kumon Kaito): Yutaka Kobayashi (小林 豊 Kobayashi Yutaka)
- Mitsuzane Kureshima (呉島 光実 Kureshima Mitsuzane): Mahiro Takasugi (高杉 真宙 Takasugi Mahiro)
- Mai Takatsukasa (高司 舞 Takatsukasa Mai): Yuumi Shida (志田 友美 Shida Yuumi)
- Takatora Kureshima (呉島 貴虎 Kureshima Takatora): Yuki Kubota (久保田 悠来 Kubota Yūki)
- Chucky (チャッキー Chakkī): KANON
- Rica (リカ Rika): MIINA
- Rat (ラット Ratto): Ren Ozawa (小澤 廉 Ozawa Ren)
- Zack (ザック Zakku): Gaku Matsuda (松田 岳 Matsuda Gaku)
- Peko (ペコ Peko): Saku Momose (百瀬 朔 Momose Saku)
- Hideyasu Jonouchi (城之內 秀保 Jyonouchi Hideyasu): Ryō Matsuda (松田 凌 Matsuda Ryō)
- Ryoji Hase (初瀬 亮二 Hase Ryōji): Atsushi Shiramata (白又 敦 Shiramata Atsushi)
- Akira Kazuraba (葛葉 晶 Kazuraba Akira): Rika Izumi (泉 里香 Izumi Rika)
- Lock Dealer Sid (錠前ディーラー シド Jōmae Dīrā Shido): Kazuki Namioka (波岡 一喜 Namioka Kazuki)
- DJ Sagara (DJサガラ Dī Jei Sagara): Tomomitsu Yamaguchi (山口 智充 Yamaguchi Tomomitsu)
- Sengoku Driver Equipment Voice (戦極ドライバー各種アイテム音声 Sengoku Doraibā Kanren Aitemu Onsei): Seiji Hiratoko (平床 政治 Hiratoko Seiji)
- Narration (ナレーション Narēshon): Hōchū Ōtsuka (大塚 芳忠 Ōtsuka Hōchū)
- Kamen Rider Gaim: Seiji Takaiwa (高岩 成二 Takaiwa Seiji)
- Kamen Rider Baron: Eitoku (永徳)
- Kamen Rider Ryugen: Daisuke Satō (佐藤 太輔 Satō Daisuke)
- Kamen Rider Zangetsu: Jun Watanabe (渡辺 淳 Watanabe Jun)
- Lock Used:
- Orange, Pine
- Banana, Rose Attacker
- Arms Change:
- Lock Vehicle:
- As part of Super Hero Time, this episode aired alongside Zyuden Sentai Kyoryuger episode 35 Brave 35: Super Awesome! Gigant Kyoryuzin!.
- Viewership: 5.2%
- Closing Screen Lockseed Collection:
- It's unknown how Kouta got back from the Helheim Forest. But presumably, he either rode the Sakura Hurricane at sufficient speed, just like Kaito, or he found another dimensional rip by accident.
- TV Asahi's official summary for 「誕生！3人目のぶどうライダー！」
- Toei TV's official episode guide for 「誕生！3人目のぶどうライダー！」