The top one is Crona's sex so it's what he biologically is. Gender is what YOU process as. Crona has never clarified for us so yes it is unknown. Either way Crona is still my favorite. Right above Kid.
Soul Eater Maka and the other students at the Death Weapon Meister Academy must kill 99 evil humans and one witch, absorbing their spirits when they die. As they go about this task, Maka and her human weapon, Soul, strengthen their bond.