Devastated by the death of his son, an American man named Thomas barricades himself in his New York bedroom for three years, leaving his apartment only at night to pick up food. This shutting away is known in Japan as hikikomori, and Thomas's desperate wife, Silke, decides to hire a young Japanese woman, Megumi, who has been trained to lure such people back into society. But the "rental sister"—as such women are called in Japan—has had her own secret, shattering experience. Her young brother, now dead, was also a hikikomori and Megumi has buried her pain and her anger in a fast life spent in nightclubs with anonymous men.

What will happen when the lives of these three needy people triangulate? Strange, erotic, mesmerizing, this brilliant and tender novel mirrors both East and West in its search for healing.