Hanaka Busujima

Always seen masked till Buso Renkin After, the epilogue chapter. She cares deeply about Hiwatari and worries about him. In Buso Renkin After, she is revealed as an extremely shy girl. She keeps her Buso Renkin, Aerial Operator, on her at all times because of her shyness. Her special ability is that she can guess the oxygen density accurately. In the anime, she is part of the Victor Search team with Inukai, Maruyama, Chitose and Shusui, they were sent to find and kill Victor, but they were easily defeated, they only escaped when Busujima released a large cloud of smoke, giving time for Chitose to teleport the others out.

(Source: Wikipedia)