After becoming injected with a formula derived from an alien ship, a lab gorilla escapes from his containment and befriends two young boys. The alien formula causes the gorilla to grow to gargantuan size and rampage throughout the city and the boys must find a way to save their simian friend before the army takes him down.

A man brutally murders a married couple and leaves the word “ikari” (“rage”) written with their blood. The killer undergoes plastic surgery and flees. At three different locations in Japan, a male stranger appears. People suspect that the stranger might be the murderer.