Nagasawa Shiina was just your average 3rd year high schooler when her father's company went bankrupt. To ease the strain on her family, she secretly begins prostituting herself. At her first job, a mysterious masked man crashes the party... and it's someone she knows... Akumetsu is the story of Hazama Shou, who defends his own view of justice in a vigilante manner while wearing a mask and calling himself Akumetsu.