Despite his flirtatious nature, Oikawa is an excellent, well-rounded player and is extremely serious about volleyball. He's known to have a "disgusting personality" amongst both opponents and his own teammates because of his smug and outwardly flippant attitude. Oikawa also frequently makes cheerful remarks but follows up with serious or intimidating afterthoughts. He is extremely intelligent and cunning. Oikawa is ambitious and one-track-minded, the main reason he pushes himself too hard.