Pinoko suddenly collapses and at the same time, Lady Yurie, head of the highly regarded Saionji family also collapses while rehearsing a traditional dance. Black Jack can find no cause for Pinoko's ailment, but is intrigued when called on to treat Lady Yurie from whom Jack removed a Teratoid Cystoma years ago. It is gradually revealed that the cyst was actually Lady Yurie's twin sister, growing within her body. Jack removed the small body parts which he later surgically reassembled to create Pinoko. Jack examines Lady Yurie and finds that she has had recurring malignant tumors, and her body is beginning to fail her. However, she insists on maintaining the family tradition of the head of the Saionji family performing the "Ascent of the White Heron" at the White Heron Temple every ten years. The temple's story tells of a heavenly maiden who took the form of a heron and descended to the land.