This is Kinji Fukasaku’s 1980 film, Fukkatsu no hi, bearing the international title Virus. It is one of the most bizarre apocalyptic films I have ever seen. An over-the-top end of the world melodrama. Unbelievable (literally), and yet nonetheless compelling. I kind of love this film. For those who don’t know, Fukasaku was the director of Battle Royale. The full length, director’s cut of Virus is sometimes difficult to get ahold of. I was happy to find it online at Internet Archive. While this version is the full-length director’s cut, I can’t seem to find the subtitles (which is too bad, because it’s a very clean print).
There is a very poor copy, that appears somewhat cropped, but is full-length and includes English subtitles on YouTube: