|Home world:||Earth (Dark Spark War Timeline)|
|First appearance:||Ultraman Ginga Episode 7:|
|Last appearance:||Ultraman Ginga Episode 11: Your Future|
|Number of appearances||5|
|Type:||Ally (Former enermy)|
|Family||Misuzu Isurugi (daughter), Unknown Wife|
|Affiliation||Lightside (Formerly Darkside)|
|Portrayed by||Hironobu Nomura|
Seiichiro Isurugi (石動誠一郎 Isurugi Seiichirō) is the father of Misuzu Isurugi and one of the secondary characters in Ultraman Ginga. He first appears as an antagonist using the Dark Dummy Spark and DarkLived into Ultraman Dark and Ultraseven Dark. After he was freed from the dark influence, he later uses a Ginga Light Spark to transform into Ultraseven.
After found himself trapped along with several people in the school while planning to turn it into a resort, Seiichiro meets Alien Nackle where he gave Seiichiro a Dark Dummy Spark via his desire to rule over everything plus the Spark Dolls of Ultraman and Ultraseven. He then ambushes Ginga after Hikaru defeats Zaragas, gaining the upper hand as both Ultraman and Ultraseven Dark but once he about to attack an unconscious Hikaru, his daughter, Misuzu Isurugi stopped him. He contacted Hikaru via telepathy and asked him to join in his conquest to conquer over everything but Hikaru refused. While Ginga battled Antlar, Seiichiro used Ultraseven Dark to destroy the monster for being weak and fought Ginga and Jean-Nine. Hikaru persuaded him to redeem while overpowered him and destroyed the evil that influenced him with Ginga Cross Shoot. The whole ordeal however made Misuzu disgusted of him and causing her to be influenced by Alien Nackle Gray to DarkLive into Super Grand King.
When Ginga and Jean-Nine struggle against Super Grand King, Seiichiro felt remorse of what happened to Misuzu and decided to settle things with her. This made the Ginga Shrine bestow him a Ginga Light Spark along with Chigusa and Kenta. He picks Ultraseven and UltraLives into the Ultra with Ultraman and Tiga to restrain the monster. Despite being eventually defeated, his effort didn't go in vain as Misuzu regained her sense and together with Hikaru as Ginga finished Alien Nackle/Super Grand King. Seiichiro makes up with Misuzu as father and daughter embrace, and even decided not to turn the school into a resort. However, he collapsed after being affected by the Dark Spark's powers by principal Kyoko Shirai, whom was re-possessed by the dark side that revived as Dark Lugiel and destroyed the whole school. He soon regains consciousness and sings the Furoboshi School's song with everyone, and contributes a Ginga Light Spark to breaking Taro's curse. He is lastly seen observing Ginga's departure from Earth.
Powers and Abilities
- Dark Dummy Spark: Seiichiro formerly possess a Dark Dummy Spark which allows him to DarkLive between Seven and Ultraman Spark Dolls, becoming Ultraman Dark and Ultraseven Dark respectively. With this, he can effectively switch between Ultraman Dark or Ultrasevn Dark when DarkLived. Also, he can communicate with another person like Hikari through telepathy.
- Ginga Light Spark: With the Ginga Light Spark, Seiichiro can UltraLive with various Ultra or monster spark dolls. He used Ultraseven spark doll to UltraLive in this case. He can communicate with others through telepathy as well.
- Seiichiro is the first user to possess two Spark Dolls to DarkLive.
- Seiichiro is the second Dark Dummy Spark user to use a Ginga Light Spark with the first is Chigusa/Ragon.