Tsubamegaoka Private Academy - All Girls' High School, located just inside the city and has clubs a plenty. From the common ones to some freakishly impressive ones, it varies greatly. It's always okay to make one, no matter what kind of club. It's not uncommon to see students join this school for the sole purpose of making a new club. But what happens when five girls want to make a club and only one new club is allowed? Cahe Detective Club happens!

Ikuto Tōhōin is a 14-year-old boy. One day, Ikuto had a fight with his father and ran away from home. He later boarded a ship to oversea, but a huge strom hits in and he fell to the ocean. After spending a week drifting in the ocean, he arrives in an island. However, this island is weird, because Meiji era people is living there. No one could escape due to whirlpool is surrounded the island. More important is that only females living there, who really desperate to marry due to no male exist on the island. (Source: ANN)