Akira Date

Akira Date (伊達 明 Date Akira) is a combat medic who traveled the world much like Eiji Hino, who he saw in Africa during a Civil War and had an Automatic Colt Pistol bullet stuck in his brain after being shot which causes him great pain at times. When he comes back to Japan he is hired by the Kougami Foundation to be the user of the Kamen Rider Birth system as well as the first one to use it. He takes up the job as Birth so to earn one hundred million Yen for the surgery to remove the said bullet. The bullet causes him greater pain over time and starts to affect his performance in battle. After taking up Dr. Maki's offer to work for the Greeed with a bribe, he reveals that he was doing so at Kougami's behest, which would earn him the amount of money enough to afford his surgery. He was later wounded on the job to the point where he can no longer fight effectively and resigned his position from the Kougami Foundation, obtaining his money and leaves the country to get his surgery done with Shintaro succeeding him. Later, he returns after recuperating from his surgery and becomes the user of Birth Prototype Version to fight against the Greeed.

Story
Date first appeared as Birth while using the Breast Cannon on Mezool as the Mega Greeed Out of Control to damage her and release two of Uva 's Core Medals. For the rest of his time as Birth he would fight the Yummy to collect their Cell Medals while also helping some of their hosts and assisting OOO when needed. He also trains Goto to take his position after finishing his task as Birth. But over time, the bullet in his head gave him greater pain, causing him to collapse during battles. Maki bribed Date to betray Kougami and join his side, which Date accepted as he starts supporting the Greeed. But in reality, Date faked the betrayal under orders from Kougami to stop Maki from becoming a Greeed.

When the Greeed injures Date in retaliation, knocking him unconscious, it gave Goto the motivation to use the Birth Driver and avenge Date's "death". Though it turned out that he was in no mortal danger from the Greeeds' attack, Date decides to let Goto become the new Kamen Rider Birth. He uses the danger policy he signed with the Kougami Foundation to collect ¥50 million so he can travel abroad to have surgery done to remove the bullet from his brain. Along with the ¥50 million that Maki paid him, he now has the ¥100 million yen he wanted for his surgery and to set up a medical school in the country where he and Eiji were involved in a civil war. Later, he returned to Japan once again and became the user of Kamen Rider Birth Prototype Version to fight against Greeed.