Akaso Eiji is a Japanese actor and model, known for playing Ryuga Banjou in Kamen Rider Build. He is currently represented by Tristone Entertainment.

He belonged to the Nagoya model office "FORM JAPAN" when he was in his teens. He was active as a model and talent under the name Mamoru Akaso (赤楚 衛, Akaso Mamoru). In 2010, he joined the local idol group "BOYS AND MEN" in Nagoya, working on stage performances and regular appearances of variety shows. Eiji is said to have left "BOYS AND MEN" in 2011. Originally, he entered the entertainment agency because he wanted to be an actor and not an idol.