Age: 22
Height: 176 cm
Players data: No.1
Blood type: B
Works: none
Home: Tokyo
Bim type: timer type

Ryouta Sakamoto is the protagonist of the manga Btooom!. He is one of the top ranking players of the Btooom! game and is the best player in Japan. He is ranked #10 worldwide. He has been nominated to participate in the real life Btooom! game.

He is a regular guy in his twenties. He is of average height and weight. He has black hair and brown eyes. He wears a dark gray, buttoned shirt and regular black pants. He also wears a black belt. As any other Btooom! player, he has an IC chip implanted into his left hand.

Later on in the story, he wears a black, long-sleeve shirt with a circle design on it. Inside the circle is the word "Btooom!" and the phrase "Soldiers, be ambitious." As seen on the cover of Btooom! 06, the circle design is light blue and the text is white.

It was later on revealed that it was his mother who put him up for nomination, apparently, because she can no longer take his lack of direction and his disrespect for her and his step father, she later on regrets what she did.