19--. Tenka Taihei is a Japanese man caught in a civil war in the Southeast Asian country Paipania (which was under a dictatorship). He meets Otomono Kuronushi, a Japanese doctor, but the two are captured and sent to a research institute where artificial insemination experiments are being conducted. There, it is discovered that Taihei's sperm had two tails instead of one, resulting in his children being born a 'third' sex.

Seven years later, Taihei is now married, but he had promised Kuronushi that he would have his sperm frozen. Yet, another seven years later, there are children born from his frozen sperm of this 'third' sex. Just what happened, and what will be the future of these children?

Volumes 81 and 82 of the Osamu Tezuka Complete Works