He admires Rin to the point of wanting to specialize in two swimming styles (breaststroke and freestyle), just like him, and does anything he can for Rin. He is a hardworking swimmer who recognizes his own limits, but often pushes himself to extremes in trying to improve. He is a friendly and slightly chatty person, sometimes saying a little too much, like when he mentions that all the Iwatobi swim team members have girly names only to be reminded by Rin Matsuoka's glare that Rin also has a girly name. His swimwear is a purple and yellow square-leg swimsuit, and he is sometimes seen wearing a Samezuka Academy jacket. A notable feature of his is a beauty mark, which is located diagonally under his right eye.
He appears to be the shortest member of the Samezuka swim team, but nevertheless, is about average height. Aiichiro has light blue eyes and short gray hair with straight bangs.
