This article is about a/an ally in Kamen Rider Blade.

Kei Karasuma (烏丸啓 Karasuma Kei) is the President of BOARD and Amane's second father. A 48-year-old professor who created the Rider systems 01 and 02 (Garren and Blade), as well as the Leangle System (03), while he was under control of Isaka. During his travels, he befriends Noboru Shima, whom he entrusted the Rouze Absorbers to despite knowing he was an Undead. He is also aware of the side effect of Kazuma's King Form as well as Tennoji's plans of the fake battle fight.

Kamen Rider Blade: Missing Ace

In Missing Ace, 4 years after the series ends, he and Sakuya discover The Stone of Relief and cracked the seal. Later, he tried to cover all 53 cards (including Black Joker) after they witness the creation of Vanity Card (which indicates the presence of another Undead), when Albino Joker appeared and unsealed Undeads, who attacked and killed Karasuma. His death was covered up by Sakuya Tachibana from everyone except the Kamen Riders and Amane herself.