Titular protagonist of Kamen Rider Build, Sento Kiryu is an amnesiac scientist working for Touto, one of the three governments of a Japan physically and politically split by a massive wall created by the Pandora's Box, a mysterious artifact brought from Mars. Besides scientific work, he also moonlights as Build, fighting off the Smash, mutated humans experimented upon by the mysterious Faust organization.
As Build, Sento uses Fullbottles, which were his own creation, to change his appearance and combat capabilities, using a combination of Fullbottles based on organic and inorganic matter, such as his default blue-and-red RabbitTank form.
