In a world where the development of artificial organs has advanced, the Charteau sisters live as if they are hiding from society. The artificial heart created by Olga, the beautiful older sister who was forced out of the research institute eight years ago, was revolutionary.
Olga and Nito secretly perform a transplant surgery to escape from dark intentions.
However, a pursuer approaches the big mystery that these two have...!? Love and life, sacrifice and ego. A story about a hidden heart!