Oikawa has chocolate brown hair that extends outwards, and eyes similar in color to his hair. He has a pretty decent height for a volleyball player, standing a little over six feet tall. Oikawa also frequently makes light-hearted comments, but follows them with a serious or intimidating tone. Despite his flirtatious, dramatic and lackadaisical exterior, Oikawa is extremely intelligent and cunning. He is Japanese nationalized, he knows how to speak Japanese, English and a little Spanish.