Kasumi Zenkuji

Kasumi Zenkuji, also known by her real name Kasumi Yumioka is an 18 year old young lady, who always gets what she wants. Usually accompanied with her maid, Azusa Yumioka (her biological mother in disguise).

Biography
Kasumi actually a child adopted by the Zenkuji family. Due to this, her adopted siblings consists of the oldest brother, Toshihide Zenkuji and his wife Asami Zenkuji and her older sister Reiko Zenkuji always secretly tries to get rid of her so she won't get the family's inheritance. Tired of her siblings for fighting over the family's inheritance, she seeks Philip's help to solve the confict which he agrees to help her out. Later, both Zoo Dopant and Zero Dopant appears. The Zero Dopant is actually a hired assassin from the Museum to assassinate Kasumi, Zero Dopant is able nullify peoples energy upon physical touch. Meanwhile,The Zoo Dopant has the powers various animals. It’s described as one of the stronger Memories, just like the Fang Memory, Zoo Memory has it’s own will. Philip has to transform into Kamen Rider Double FangJoker, and it’s explained that Shotaro’s compatibility with the Joker Memory is what keeps the Fang Memory from going berserk. Thus, Joker is the only Memory that can be used with Fang. Terui fights as Kamen Rider Accel, but none of their attacks are working as Shotaro was actually infected by flu. Philip and Terui lose, not only that the Fang Memory is broken after the fight.

Shroud shows up at the agency and says that Shotaro is only hindering Philip. Without Fang, Philip is unable to fight. However, Shroud leaves the Lost Driver behind her before disappearing. Philip ends up having to use the Lost Driver along with his Cyclone Memory and fights the Dopants. Fighting with the wind, Kamen Rider Cyclone manages to defeat Zero with the help from Accel. Cyclone lets Philip absorb wind and use it as strength, it also increases his mobility. His special attack is some sort of aerodynamic Rider Chop, but it remains unnamed. The Zoo Dopant is revealed to be Toshihide, but later his Memory is stolen by the maid, Azusa Yumioka. Azusa is then revealed to be Kasumi’s real mother. She stole the Memory in order to protect her daughter. But that doesn’t last long as Asami steals it back and pretty much everyone in the Zenkuji family wants Kasumi dead. After fighting as Kamen Rider Cyclone by himself, Philip realizes how much Shotaro means to him. That he couldn’t possibly fight alone like this, that he needs his partner Shotaro.

Fortunately, Shotaro just recovered for the final battle. They transform together into their new form, Cyclone Joker Xtreme. Accel is present to help with the fight. Because of Zenkuji’s vast resources, they get a bunch of unimportant people to use Gaia Memories and fight for them. The final battle consists 13 Dopants in total, Toshihide as Zoo, Asami as Queen Bee, Reiko as Flower, then there’s Elephant, Dolphin, Salamander, Fish, Ape, Bird Dopant, Cockroach Dopant and 3 Bee Dopants, a mass produced cheap version of Queen Bee.

After the fight is over, Philip who has hidden the Lost Driver, swears that he’ll never use it again. At the end Kasumi says she’s developed feelings towards Philip throughout their time together, but Philip doesn’t pick up on this at all.

Trivia

 * Kasumi is the second person which have feelings for Philip as the first one is Elizabeth.