The Denkigai siblings, Tamotsu and Niwaka, come across "Bugged Ones" - vampires cosplaying monsters - while shopping in Akihabara. These malicious creatures bite and take over their victims, creating mayhem throughout the city. Tamotsu becomes a victim, but fortunately, a mysterious figure, Matome Mayonaka, who possesses a baseball bat, comes to his aid. Despite facing numerous Bugged Ones, they collaborate to fight them off. Tamotsu, however, sacrifices himself to save Matome but is severely wounded. Unable to find a different solution, Matome raises Tamotsu to become a high-level Bugged One, similar to her. Together with Arisa Ahokainen, an avid cosplayer otaku, they form "The Electric Mayonnaise." Their ultimate goal is to expose the Bugged Ones to sunlight by tearing off their attire and defeating them.