Unkai, the main character, is laid off from his word due to economy down term.
Mina Saeki, a full time worker at his work, humiliates him for his lay off.

Being furious, he stalks Mina to her home.
There, he learns that she is a daughter of apartment building owner, which beats his emotion even more.
Being jealous, he starts to think of raping Mina.

Moreover, he finds the apartment has many beautiful residents with big boobs.
He then decides to r*pe all of the residents in the apartment building.

[From DLsite English]