The captain and setter of the Aoba Jousai High School Volleyball Club. Oikawa was also Kageyama's senpai when they were attending Kitagawa Daiichi. According to Kageyama, he is a very talented setter and volleyball player with a bad personality. Oikawa also frequently makes cheerful remarks, but follows them up with serious or intimidating afterthoughts. Despite his flirtatious and blasé exterior, Oikawa is extremely intelligent and cunning, to the point of his own teammates stating they wouldn't want to be friends with him because he figures out everyone's weakness. He holds a grudge against Kageyama, whom he mockingly calls Tobio-chan. This is due to his feelings of inferiority when compared to Kageyama, who has been hailed as a genius setter since their time spent at Kitagawa Daiichi. Kageyama can unintentionally bring out the more childish or rash aspects of Oikawa's personality. (Source: Haikyuu!! Wiki)

This character is named differently depending on the translator. Jellal is a literal romanization; Gerard is an alternate romanization, completing the sounds that the Japanese language can't phonetically sound. Jellal is introduced under the alias of Siegrain, a young member of the Magic Council and can be considered the main antagonist of the series. His design is the same as that of Rave Master's Sieg Hart, Hiro Mashima's previous work, as a form of fan service. With his "underling" Ultear he typically disagrees with the rest of the Council, typically by showing leniency to Fairy Tail.