Having Samurai blood may be a status symbol in Japan, but as businessman Tsukasa Atsumi discovers, it also makes one a target for demonic attacks. Fortunately, he's rescued by ninja Shizuri Ideura, who specializes in fighting demons, so the two decide to form a contract wherein she'll move in to provide 24-7 anti-demon coverage. It's not like hiring a maid service, though, as Shizuri is also an otaku shut-in who'd rather spend her time playing videogames and lazing about the house than fading into the background. However, given that she's also uber-adorable, just how far away can the romantic complications be?