Young company president Kosei Saryo begins keeping a “girl pet” who looks exactly like his late lover, Sayuki Fujino. Meanwhile, Sayuki’s younger brother Sota, convinced that Kosei was the one who drove his sister to her death, acquires a “girl pet” of his own in order to carry out his revenge.

As both men project their unresolved emotions onto their “pets,” their lives edge closer toward confrontation, entwined in a dangerous cycle of love, grief, and vengeance.