Oliver Aiku

Aiku is a very tall and muscular young man with shaggy, dark purple hair with lime green tips and short facial hair. As a child, his facial structure stayed the same, just becoming sharper and more refined as he grew facial hair. Aiku is heterochromatic, and his eyes are different colors, with his left eye being green and his right eye being purple. However, in the anime, his right eye's color was changed to blue.

During the Japan National Representative match, Aiku dons the official white with red trim U-20 jersey and shorts and wears the captain's band on his left sleeve. Under that, he wears a black shirt and gloves. Aiku also wears black cleats with red edges.

When Aiku was a child, he wanted to become the best striker in the world, but his coach and other adults tainted his dream with the philosophy of "playing for others." He lost the will to become the best striker in the world in time but decided wholeheartedly to become the best defender in the world to spite all the adults and coaches that told him to play for others and refused to help him pursue his own goals. He promised himself, though, that if a "true striker" ever appears, struggling to bloom in Japan, he will do whatever it takes for them to shine and prevent them from being tainted like he was.

Aiku lives up to his title as captain as he is the defender and peacekeeper of the Japan U-20 team and its players, as seen when he stops Ryusei Shido from harming their Ace and also keeps their Ace and other members in check with his charisma. Despite his seemingly jovial and friendly manner, Aiku changes dramatically when on the field, becoming a dangerous and highly skilled threat. Aiku can be a bit reckless, for he unnecessarily bet the fate of him and his team for a chance to beat the Blue Lock Eleven properly and prove something to himself.