Takahashi Yuma, 24, is tired of the relationships in his company and decides to change jobs.
When he gets off at a station a short distance from home to take a detour after a long time, he finds three beautiful women being entangled with three dorky guys.
He helps them out as a conditioned reflex.
He realizes that he (Takahashi Yuma) and the girls (the three Kirie sisters) used to live next door to each other. He also learns that he once saved them from a terrible fate.
The three Kirie sisters’ dark and heavy love begins to move.