Oooaaa is uhmmmmmmmmmmmmm it is uhhhhh uhh it's an uhhhhhm it is uhhhhh... I DON'T KNOW, OK? IT'S LITERALLY A BUNCH OF O'S AND A'S PUT TOGETHER FOR NO PARTICULAR REASON!
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi