There exists a city known as Mihito City where all men have mysteriously disappeared leaving it as the only city in the world with a 100% female population. Many have tried to find out why men have suddenly gone missing but after months and even years of searching, no explanation has been found for why this happened.

In this city there are also Tinies, which are 1 inch tall humanoid creatures that resemble men and were mass produced by a small company in Mihito City. Tinies are largely seen by the population of Mihito City as pests, pets or even food. Unbeknownst to everyone however, the men were actually turned into Tinies as part of an experiment led by a researcher named Saeki Runa.