After six years apart following their parents' passing, Akito and Akiko have finally reunited and are living together, but Akiko has developed romantic feelings towards her brother. Akito, on the other hand, only sees his sister as family. To further complicate matters, three new girls - Anastasia, Arashi, and Ginbei - have moved into their apartment, making it impossible for Akiko to spend any alone time with her brother. Adding fuel to the fire, these new girls are also vying for Akito's affections, and their explicit behavior may prove too much for any man to handle.