A virus caused people all over the world to start ABO differentiation. The male protagonist accidentally traveled through time and came to the day when the world was divided. Unfortunately, he differentiated into O and encountered an embarrassing period. He fell softly into the arms of someone. It turned out that this person was A and released pheromones crazily.
The male protagonist is incompetent and furious: "This man must be sick!!!"
Intention: eternal love