Tatsumi is a virus researcher in the General Division who has a growing problem: his body releases Estrus pheromones and he needs to have sex to calm his heat... but Tatsumi has haphephobia. Suou, a man who joined the General Division due to an incident caused by Tatsumi's experiment, is the perfect match for Tatsumi's heat every night – and he can't hold back his desire to monopolize him.