|Name: Akira Date|
|Designation: Kamen Rider Birth, Kamen Rider Birth Prototype|
|Weapons: Birth Buster, Birth CLAWs|
|Gear: Birth Driver|
|Akira Date became the first regular user of the Kamen Rider Birth system at the Kougami Foundation. Before that, he traveled the world. As Kamen Rider Birth, Date gave himself a task to earn 100 million yen while doing his job, thus proclaiming that he'll be taking all the Cell Medals from here on out by gathering them into a milk tank he carries around when not fighting. Date is a people person, admitting his own desire, yet he makes it a personal rule to not use others to reach his goal, as well as not doing anything that will make he himself cry. Though he dislikes reading manuals and has a tendency to mix up names, but Date enjoys getting the job done perfectly. Date is also known to love eating oden, even making oden in Maki's research lab, where he takes up residence and regularly makes a mess out of, much to the scientist's dismay. When he sees Eiji's picture in the Cous Coussier, he remarks that he may have seen him before he returned to Japan. Date is also training Shintaro Goto to take up the mantle of Kamen Rider Birth once his job with the Kougami Foundation is done. Before battle, Date tends to say "Now, let's start earning" Like Kamen Rider OOO, Kamen Rider Birth's powers stem from the O Medals that power the Greeed and their Yummy creations. However, Kamen Rider Birth was developed by the Kougami Foundation's Kiyoto Maki to utilize the power of the Cell Medals.
Among Birth's arsenal is the Birth Helmood which provides a head-up display to the system's user. On Birth's armor are capsules called Receptacle Orbs, similar to gashapon capsules, in which the Birth CLAWs system is installed in until a Cell Medal is used to summon the weapons. Date's medical condition is then revealed to Shintaro after it begins to worsen to where it affects him in in battle. Maki then bribed Date to betray Kougami and join his side, which Date accepted as he starts supporting the Greeed, with 50 million yen up front. But in reality, Date faked the betrayal under orders from Kougami to stop Maki from becoming a Greeed. When the Greeed injure 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 Greeed's 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 yen, making a full 100 million yen, and thus travels abroad to have surgery done to remove the bullet from his brain. Date later returns to Japan, now using the Kamen Rider Birth Prototype suit to fight the Greeed. After the end of the Greeed conflict, Date returns to being a traveling medic.