Yuuma Kousaka, a high schooler resistant to the zombie virus, has to periodically kiss Mai Tsukishiro to stop her from turning into a zombie. When they come across more survivors--a pair of college girls--he decides it's best not to tell them that he and Mai are both infected. However, after the new arrivals see the two of them making out, Yuuma and Mai are forced to keep up the facade and pretend to be in a relationship...something his real girlfriend, Haruka Hyuuga, does not find entertaining.