|This article is about a/an episode in Kamen Rider Kiva.|
Supersonic: Saga's Fight (スーパーソニック・闘いのサガ Sūpāsonikku: Tatakai no Saga) is the thirty-third episode of Kamen Rider Kiva.
In 1986, after defeating Dogga for attacking her, Maya is surprised to see Otoya remaining in spite of knows her true identity as a Fangire. Walking with her, rather than fight her, Otoya asks Maya for the answer Maya asked him. Revealing that it is the violin meant for the violinist that brings out the talent, Otoya remembers his encounter with Ōmura and his Black Star, as Maya offers to teach him the violin-making arts before leaving to see Taiga with Kurosawa worried about his mistress' interest in humans. Maya then heads to Otoya's house as they begin their work on the "ultimate violin", with Yuri looking on with a broken heart before walking off.
In 2008, Kiva's fight with the Moose Fangire is watched by Saga, who takes his leave after the Fangire retreats and Kiva reverts as he walks into Mio, who pleas him not to let her go as Wataru promises her that he'll stay by her side. After Taiga finishes a meeting with a young man named Numakawa, he sees Wataru and invite him out to dinner in order for him to meet his fiance. When Wataru finds out the fiance is Mio, Wataru is shocked as he gets down in the dumps that his girlfriend is seeing his best friend. Later after a talk with Nago, who wishes to know more about Maya, Mio arrives to explain that the engagement was arranged and she has no choice in the matter. But her words fall on deaf ears as Shizuka escorts Mio out, with the heart-broken girl running into Kurosawa who attempts to kill Mio when Taiga interferes, disowning the Fangire's aid for his attempt. The next day, clueless of the feelings of Wataru and Mio, Taiga helps Mio with a second chance to execute Numakuwa, who is a Fangire she let go in a previous confrontation. But Mio could not do it as the Tortoise Fangire runs into Kurosawa who attempts to clean up her mess just as Wataru arrives and fights the Moose Fangire. But as Kiva assumes Emperor Form and uses the Dogga Hammer to destroy the Moose Fangire, a weakened Numakuwa runs into Taiga who reveals himself as the new King of the Checkmate Four, Kamen Rider Saga, who slays the Tortoise Fangire with Kiva's insignia in the sky.
- Wataru Kurenai (紅 渡 Kurenai Wataru): Koji Seto (瀬戸 康史 Seto Kōji)
- Otoya Kurenai (紅 音也 Kurenai Otoya): Kouhei Takeda (武田 航平 Takeda Kōhei)
- Keisuke Nago (名護 啓介 Nago Keisuke): Keisuke Kato (加藤 慶祐 Katō Keisuke)
- Megumi Aso (麻生 恵 Asō Megumi): Nana Yanagisawa (柳沢 なな Yanagisawa Nana)
- Yuri Aso (麻生 ゆり Asō Yuri): Yu Takahashi (高橋 優 Takahashi Yū)
- Shizuka Nomura (野村 静香 Nomura Shizuka): Rina Koike (小池 里奈 Koike Rina)
- Kivat-Bat the 3rd (キバットバットⅢ世 Kibattobatto Sansei, Voice): Tomokazu Sugita (杉田 智和 Sugita Tomokazu)
- Tatsulot (タツロット Tatsurotto, Voice): Akira Ishida (石田 彰 Ishida Akira)
- Riki (力 Riki): Eiji Takigawa (滝川 英治 Takigawa Eiji)
- Maya (真夜 Maya): Saki Kagami (加賀美 早紀 Kagami Saki)
- Mio Suzuki (鈴木 深央 Suzuki Mio): Yuria Haga (芳賀 優里亜 Haga Yuria)
- Taiga Nobori (登 太牙 Nobori Taiga): Shouma Yamamoto (山本 匠馬 Yamamoto Shōma)
- Akira Kido (木戸 明 Kido Akira): Houka Kinoshita (木下 ほうか Kinoshita Hōka)
- Kurosawa (黒沢): Kazuoki Takahashi (高橋 和興 Takahashi Kazuoki)
- Numakawa (沼川): Makoto Sakamoto (坂本 真 Sakamoto Makoto)
- Tortoise Fangire (トータスファンガイア Tōtasu Fangaia, Voice): Yoshimitsu Shimoyama (下山 吉光 Shimoyama Yoshimitsu)
Kiva: Kiva Form, Emperor Form
Saga: Saga Form
- As part of Super Hero Time, this episode aired alongside Engine Sentai Go-Onger episode 31, GP 31: Idol Debut.
- Viewership: 6.4%
- This marks the only time that Kiva uses Dogga Fever.
- This marks the first transformation of Kamen Rider Saga
Blu-ray Box 3 comes with 16 episodes.