Despite his flirtatious nature (which makes him famous amongst female students) and childishness, 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 afterthoughts. He is extremely intelligent and cunning but can be very attentive and caring.