The story of two sisters born with different bodies. Older sister Soo-hwa who failed with her business lives with her younger sister, Bo-hwa and his husband. Soo-hwa's husband Ki-hyeon confides in Bo-hwa's husband, Seong-goo everytime they have sex, worrying about Soo-hwa's coldness. Seong-goo on the other hand says that Bo-hwa is more passionate, suggesting for them to change partners...