Yuunagi-Sou This old dormitory is a mysterious place. it is protected by a mysterious power that can not be approached by ordinary people. Located in the middle of the city, within a bamboo grove, Yuunagi-Sou quietly resides....

Yuunagi-Sou has only had women living there, including the manager. They are all beautiful, but each one has something eccentric about them.

They were all beautiful girls.... with an "S-Class" ability.

The protagonist of this story, Saikawa Rin, has returned to his hometown for the first time in a long time. When he began looking for an apartment, he stumbled upon Yuunagi-Sou. The building is old but grand and all the residents were beautiful women. He was happy to move in.

But he does not know the truth. That only "S-Class" people can move in.... He does not know yet that he is in fact an "S-Class Boy"