When an embarrassing picture of Rushuna along with Yajiro's heirloom blade are stolen, they set off with Teppa after the culprit - who turns out to be none other than Rushuna's Armsmaster and adoptive father! But they soon find themselves surrounded by Shiki - Death Machines equipped with Thermal Targets - and the Iron Mask Baron himself! Rushuna is then stolen away and brought before her "Double," her adopted older sister... who seeks revenge!
