In a world with an alternate history, a great war finally comes to an end leaving the earth diseased and polluted. The geneticist Dr. Azuma vies for support from the government for his neo-cell treatment that he claims can rejuvenate the body and regenerate humankind. The government leaders, guarding their own deeply entrenched powers, turn down the professor. Driven to complete his work, Dr. Azuma accepts a secret offer from a sinister faction of the powerful military. After an incident occurs in Dr. Azuma's lab, a race of mutant humans known as the Shinzo Ningen are unleashed upon the world. Now only the warrior known as Casshern, reincarnated with an invincible body, stands between the Shinzo Ningen and a world on the brink of annihilation.

Still Walking is a family drama about grown children visiting their elderly parents, which unfolds over one summer day. The aging parents have lived in the family home for decades. Their son and daughter return for a rare family reunion, bringing their own families with them. They have gathered to commemorate the tragic death of the eldest son, who drowned in an accident fifteen years ago. Although the roomy house is as comforting and unchanging as the mother's homemade feast, everyone in the family has subtly changed.