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 darkness' influence, he later uses a Ginga Light Spark to transform into Ultraseven.