Oikawa was in a popular gang—The Seijoh Brawlers. He was a popular street racer. His code name was Cypher, because he was so hard to understand or decipher. you were at one of his races because your cousin Haijime Iwaizumi was also a part of the Seijoh Brawlers, his nickname was Indigo. Currently you were with Oikawa in his car while watching Haijime's race.