Wataru Ômae

From Earth's pollution a new monster is spawned. Hedorah, the smog monster, destroys Japan and fights Godzilla while spewing his poisonous gas to further the damage. (imdb)

Former playmates both long ago abandoned by their parents, recall their youth and fall in love. A young man, deserted as a child by his mother, and a young woman, deserted in childhood by her father, meet and recall their days as playmates. When a romance develops between them, the man's foster parents express their disapproval and the woman's teacher claims they are too young for marriage; and the two lovers part. (The Toho Studios Story: A History and Complete Filmography)

Osaka in the early 1600s, aftermath of the historical Battle of Sekigahara; a group of orphan children are wandering through the battlefield scavenging for armour when they encounter a young boy named Sasuke with magical powers he says came from a meteor that crashed onto the Earth. (imdb)

A scientist and two children are accidentally transported into a future dominated by primates.