He is the most unlikely hero of all the ARMS subjects. Takeshi is smart, skinny, sensitive, solitary, and timid, the classic target for high school bullies. Takeshi was constantly tormented at school, which caused his ARMS to first activate. Takeshi then became even more isolated, genuinely loathing his own body and his cowardice. After Takeshi meets Ryo and his fellow ARMS he finally realizes he is not alone. He also realizes his family and friends are what he really cares about, and that he must fight to protect them. Takeshi then becomes a brave, loyal, and powerful member of the team. Since sustaining crippling injuries at the hands of Kou Karunagi, Takeshi and the White Rabbit was in a dormant, cocoon-like state and was communicating with Alice while the rest of the team was fighting in Carillon Tower. However, when Ryo and the Jabberwock merged with Black Alice, White Alice offered Takeshi his choice of one of many weapons, all of which would give him more power than any earthly weapon. Takeshi declined the power however, and instead took White Alice with him out of her isolation in Carillon Tower, and using their combined power they were able to attack and merge with the Jabberwock which allows White Alice to directly confront her evil half.
Takeshi's ARMS is called White Rabbit, and is concentrated in Takeshi's legs. Takeshi can run and jump incredibly fast, perform seemingly impossible midair maneuvers, and fly up to several hundred feet. Takeshi is also capable of performing astoundingly fast kickboxing capable of shattering concrete and high speed acrobatic manoeuvers. To put it in perspective, he was able to weave in and out of the spinning blades of two helicopters and move and attack so fast that even the Red Caps, using their telepathic abilities to anticipate his moves, couldn't keep up with him. The White Rabbit's nano-machines allow Takeshi to heal injuries much faster than a normal human. White Rabbit's ultimate form is a winged humanoid that can fly faster than the speed of sound. Like the Knight, White Rabbit is also ready to destroy Jabberwock if he gets completely out of control.
(Source: Wikipedia)